Information processing apparatus, information processing method, and information processing program

ABSTRACT

An information processing apparatus includes a selection unit selecting at least a part of a text included in contents, an acquisition unit acquiring a processing result of natural language processing for the part of the text selected by the selection unit, a specifying unit specifying a predetermined part of the text based on the processing result acquired by the acquisition unit, a detection unit detecting a keyword from the predetermined part of the text based on the processing result acquired by the acquisition unit, a tag generation unit automatically generating a tag in accordance with the keyword detected by the detection unit, and an association unit associating the tag generated by the tag generation unit with the predetermined part of the text.

BACKGROUND

The present disclosure relates to an information processing apparatus,an information processing method, and an information processing program,and more particularly, to an information display system structuredusing, for example, an information display terminal that displays anelectronic book such as a novel or a magazine transferred as digitaldata.

A portable retrieval apparatus according to the related art reads anddisplays, as dictionary information, an English word translated from aJapanese word, or a usage or the like of the English word from adatabase for an electronic dictionary, for example, when a user inputsthe Japanese word using a keyboard and operates a retrieval start key.

When the user operates a cursor key or a touch panel with an input pento select desired words, a usage, or the like in the dictionaryinformation in the state where the dictionary information is displayed,the portable retrieval apparatus underlines the selected words, theusage, or the like.

Thus, the portable retrieval apparatus can be used just as a userunderlines desired words, a usage, or the like in a paper dictionarywith a pencil (for example, Japanese Unexamined Patent ApplicationPublication No. 10-11457 (pages 3, 5, and 6)).

SUMMARY

When a user selects desired words, a usage, or the like of thedictionary information, the portable retrieval apparatus with theabove-described configuration maintains information indicating theselected words, usage, or the like.

Therefore, even when the portable retrieval apparatus displays thewords, usage, or the like once selected again, the portable retrievalapparatus can underline the selected words, usage, or the like.

However, when the portable retrieval apparatus displays the selectedwords, usage, or the like again, problems may arise in that it isdifficult to easily distinguish the selected words, usage, or the likeand usability is poor.

It is desirable to provide an information processing apparatus, aninformation processing method, and an information processing programcapable of improving usability.

According to an embodiment of the disclosure, there is provided aninformation processing apparatus including: a selection unit selectingat least a part of a text included in contents; an acquisition unitacquiring a processing result of natural language processing for thepart of the text selected by the selection unit; a specifying unitspecifying a predetermined part of the text based on the processingresult acquired by the acquisition unit; a detection unit detecting akeyword from the predetermined part of the text based on the processingresult acquired by the acquisition unit; a tag generation unitautomatically generating a tag in accordance with the keyword detectedby the detection unit; and an association unit associating the taggenerated by the tag generation unit with the predetermined part of thetext.

According to the embodiment of the disclosure, it is possible toassociate the tag with the predetermined part of the text and easilyidentify where the predetermined part of the text is located based onthe tag.

According to the embodiment of the disclosure, it is possible to realizean information processing apparatus, an information processing method,and an information processing program. The information processingapparatus includes: a selection unit selecting at least a part of a textincluded in contents; an acquisition unit acquiring a processing resultof natural language processing for the part of the text selected by theselection unit; a specifying unit specifying a predetermined part of thetext based on the processing result acquired by the acquisition unit; adetection unit detecting a keyword from the predetermined part of thetext based on the processing result acquired by the acquisition unit; atag generation unit automatically generating a tag in accordance withthe keyword detected by the detection unit; and an association unitassociating the tag generated by the tag generation unit with thepredetermined part of the text. Accordingly, since it is possible toassociate the tag with the predetermined part of the text and easilyidentify where the predetermined part of the text is located based onthe tag, usability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an overview of the circuitconfiguration of an information processing apparatus according toembodiments.

FIG. 2 is a block diagram illustrating the configuration of aninformation display system according to a first embodiment.

FIG. 3 is a block diagram illustrating the circuit configuration (1) ofa function circuit block of an information display terminal.

FIG. 4 is a diagram schematically illustrating a display of anelectronic book image.

FIG. 5 is a diagram schematically illustrating an instruction (1) of adesired part of a text by a slide operation.

FIG. 6 is a diagram schematically illustrating an instruction (2) of thedesired part of the text by a slide operation.

FIG. 7 is a diagram schematically illustrating an instruction (3) of thedesired part of the text by a slide operation.

FIG. 8 is a diagram schematically illustrating an instruction (4) of thedesired part of the text by a slide operation.

FIG. 9 is a diagram schematically illustrating the detection (1) of aninstruction range when the desired part of the text is traced in astraight line shape.

FIG. 10 is a diagram schematically illustrating the detection (2) of aninstruction range when the desired part of the text is traced in astraight line shape.

FIG. 11 is a diagram schematically illustrating the detection of aninstruction range when the desired part of the text is traced in a waveline shape.

FIG. 12 is a diagram schematically illustrating the detection of theinstruction range when the desired part of the text is parenthesized.

FIG. 13 is a diagram schematically illustrating the detection of theinstruction range when the desired part of the text is surrounded.

FIG. 14 is a diagram schematically illustrating the detection of asearch range in accordance with a first selection method.

FIG. 15 is a diagram schematically illustrating the detection of thesearch range in accordance with a second selection method.

FIG. 16 is a block diagram illustrating the configuration of a naturallanguage processing block.

FIG. 17 is a diagram schematically illustrating specifying of a desiredpart in an instruction estimation part.

FIG. 18 is a diagram schematically illustrating the configuration of abook registration table.

FIG. 19 is a diagram schematically illustrating the configuration of adesired part registration table.

FIG. 20 is a diagram schematically illustrating the configuration of akeyword registration table.

FIG. 21 is a diagram schematically illustrating the configuration of atag registration table.

FIG. 22 is a diagram schematically illustrating the configuration of akeyword association table.

FIG. 23 is a diagram schematically illustrating the configuration of atag association table.

FIG. 24 is a diagram schematically illustrating an emphasis display (1)of a desired part.

FIG. 25 is a diagram schematically illustrating an emphasis display (2)of desired parts.

FIG. 26 is a diagram schematically illustrating a display of a tag.

FIG. 27 is a diagram schematically illustrating a display of associationinformation.

FIG. 28 is a diagram schematically illustrating the configuration of afirst hierarchical index image.

FIG. 29 is a diagram schematically illustrating the configuration of asecond hierarchical index image.

FIG. 30 is a diagram schematically illustrating the configuration of athird hierarchical index image.

FIG. 31 is a diagram schematically illustrating classification ofdesired parts.

FIG. 32 is a diagram schematically illustrating a display of a firsthierarchical classification result image.

FIG. 33 is a diagram schematically illustrating an introduction of auser by an information sharing apparatus.

FIG. 34 is a diagram schematically illustrating selection reflection ofa desired part between the information display terminals.

FIG. 35 is a diagram schematically illustrating a display of an emphasisdisplay menu image.

FIG. 36 is a diagram schematically illustrating a display of arelationship notification image.

FIG. 37 is a diagram schematically illustrating a display of a testproblem generated in accordance with an importance of the desired part.

FIG. 38 is a block diagram illustrating the circuit configuration (2) ofa function circuit block of the information display terminal.

FIG. 39 is a block diagram illustrating the circuit configuration of thefunction circuit block of the information sharing apparatus.

FIG. 40 is a flowchart illustrating an emphasis display processingsequence.

FIG. 41 is a flowchart illustrating a sub-routine (1) of an instructionestimation part selection process.

FIG. 42 is a flowchart illustrating a sub-routine (2) of the instructionestimation part selection process.

FIG. 43 is a flowchart illustrating a sub-routine (3) of the instructionestimation part selection process.

FIG. 44 is a flowchart illustrating a sub-routine of a keyword detectionprocess.

FIG. 45 is a flowchart illustrating a sub-routine of a tag generationprocess.

FIG. 46 is a flowchart illustrating an information introductionprocessing sequence (1).

FIG. 47 is a flowchart illustrating an information introductionprocessing sequence (2).

FIG. 48 is a flowchart illustrating an information sharing processingsequence.

FIG. 49 is a block diagram illustrating the configuration of aninformation display system according to a second embodiment.

FIG. 50 is a block diagram illustrating the circuit configuration of ahardware circuit block of the information display terminal.

FIG. 51 is a block diagram illustrating the circuit configuration of ahardware circuit block of the information sharing apparatus.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, preferred embodiments (hereinafter, simply referred to asembodiments) of the disclosure will be described with reference to thedrawings. The description will be made in the following order.

1. Overview of Embodiments

2. First Embodiment

3. Second Embodiment

4. Modified Examples

1. Overview of Embodiments

First, the overview of the embodiments will be described. After theoverview of the embodiments is described, first and second embodimentswill be described as specific examples.

In FIG. 1, Reference Numeral 1 denotes an information processingapparatus according to the embodiments. A selection unit 2 of theinformation processing apparatus 1 selects at least a part of a textincluded in contents. An acquisition unit 3 of the informationprocessing apparatus 1 acquires a processing result of natural languageprocessing for the part of the text selected by the selection unit 2.

A specifying unit 4 of the information processing apparatus 1 specifiesa predetermined part of the text base on the processing result acquiredby the acquisition unit 3. A detection unit 5 of the informationprocessing apparatus 1 detects a keyword in the predetermined part ofthe text based on the processing result acquired by the acquisition unit3.

A tag generation unit 6 of the information processing apparatus 1automatically generates a tag corresponding to the keyword detected bythe detection unit 5. An association unit 7 of the informationprocessing apparatus 1 associates the tag generated by the taggeneration unit 6 with the predetermined part of the text.

The information processing apparatus 1 is capable of associating the tagwith the predetermined part of the text and easily identifying where thepredetermined part of the text is located based on the tag. Thus, theinformation processing apparatus 1 can improve usability.

2. First Embodiment 2-1. Configuration of Information Display System

In FIG. 2, Reference Numeral 10 denotes an information display systemaccording a first embodiment. In the information display system 10, forexample, two kinds of information display terminals 11 and 12, which arespecific examples of the information processing apparatus 1 describedabove, can communicate with an information sharing apparatus 14 via anetwork 13.

The information display terminals 11 and 12 receive and store (that is,acquire) electronic book data of an electronic book such as novels,magazines, or learning materials transferred as digital data from theinformation sharing apparatus 14 or an electronic book supply apparatus(not shown) via the network 13. Moreover, the electronic book such aslearning materials may be a textbook, a reference book, or the like.

The information display terminals 11 and 12 can also receive and store ahome page, a report, or the like publicized as digital data on thenetwork 13 as the electronic book data of an electronic book from aninformation supply apparatus (not shown) via the network 13.

Here, the electronic book includes a single or a plurality of pages. Inthe individual pages of the electronic book, only text may be disposedand generated throughout a plurality of rows, or a text and a photoimage for a sheet cover or insertion, an illustration image, or the likeare disposed and generated through a plurality of rows.

The electronic book data of the electronic book includes book attributedata, text data of a text for each page, and image data of a photo imagefor a cover sheet or insertion, an illustrated image, or the like.

The book attribute data stores book identification information used toindividually identify electronic books, the kinds of electronic book(hereinafter, also referred to as book types) such as books ormagazines, the titles of the electronic books (hereinafter, alsoreferred to as book titles), publisher names of the electronic books,and the like.

The text data for each page includes a page number, a text generatedwith a plurality of kinds of characters such as Hiragana and Katakanacharacters (Japanese script), Japanese Kanji characters, punctuations,and blanks through a plurality of rows, and character locationinformation indicating the positions of the characters in the text withrow and column numbers.

In the text data for each page, individual characters (actually,character codes for characters) of the text match the character positioninformation indicating the positions of these characters in the text.

When the information display terminals 11 and 12 receive an instructionto display an electronic book in the state of acquiring the electronicbook data, the information display terminals 11 and 12 appropriatelydisplay the text for each page of the electronic book together with aphoto image for a cover sheet or insertion, an illustration image, orthe like as electronic book image based on the electronic book data.

When the information display terminals 11 and 12 display the electronicbook image, the information display terminals 11 and 12 are configuredso that users can select a predetermined part (hereinafter, alsoreferred to as a desired part) of a desired paragraph, a desired clause,a desired word, or the like in the text of this electronic book image.

When the information display terminals 11 and 12 receive an instructionto display a desired part in the text of the electronic book image fromthe users in a state of displaying the electronic book image, asdescribed below, the information display terminals 11 and 12 specify anddisplay the desired part in the text in the emphasis manner.

When the information display terminals 11 and 12 display the desiredpart of the text in the emphasis manner, the information displayterminals 11 and 12 generate and store desired part registration data toregister the desired part displayed in the emphasis manner.

In this way, when the users select the desired part in the text of theelectronic book image being displayed, the information display terminals11 and 12 can maintain the selected desired part as the desired partregistration data.

Accordingly, when the users displays the electronic book image in whichthe desired part is selected from the text again, the informationdisplay terminals 11 and 12 can display the desired part in the emphasismanner in the text of the electronic book image again based on thedesired part registration data so that the users can confirm thepreviously selected desired part.

Moreover, the information display terminals 11 and 12 transmitbook-associated data, which includes the electronic book in which theusers select the desired part or various kinds information regarding thedesired part, to the information sharing apparatus 14 via the network13.

When the information sharing apparatus 14 receives the book-associateddata transmitted from the information display terminals 11 and 12, theinformation sharing apparatus 14 stores the book-associated data. Forexample, when the information sharing apparatus 14 receives a requestfor supplying information regarding desired parts selected with otherinformation display terminals 11 and 12 from the information displayterminals 11 and 12, the information sharing apparatus 14 generatesdesired part information supply data for supplying the informationregarding the desired parts based on the book-associated data.

The information sharing apparatus 14 transmits the desired partinformation supply data to the information display terminals 11 and 12.Thus, the information sharing apparatus 14 displays the desired partsselected in the text of the emphasis manner in the electronic book bythe other information display terminals 11 and 12 in the text of thesame electronic book image based on the desired part information supplydata in the information display terminals 11 and 12.

Thus, when the plurality of information display terminals 11 and 12share the desired parts selected by the other information displayterminals 11 and 12 using the information sharing apparatus 14 anddisplay the same electronic book image, the information displayterminals 11 and 12 can display the shared desired parts in the emphasismanner.

2-2. Hardware Configuration of Function Circuit Block of One InformationDisplay Terminal

Next, the hardware configuration of the function circuit block of oneinformation display terminal 11 of the two kinds of information displayterminals 11 and 12 will be described with reference to FIG. 3.

As shown in FIG. 3, the one information display terminal 11 includes acontrol unit 20 that controls the entire information display terminal11. The information display terminal 11 includes a display unit 21 thatdisplays various operation images or an electronic book image.

The information display terminal 11 further includes an operation unit22 that is configured by a touch panel installed so as to cover adisplay surface of the display unit 21 or operation keys installed onthe housing surface of the information display terminal 11.

When the operation unit 22 is operated by key operation such as pressingor rotating of the operation keys, the operation unit 22 transmits anoperation command corresponding to the key operation to the control unit20. Thus, the control unit 20 performs a process corresponding to theoperation command given from the operation unit 22.

The touch panel serving as the operation unit 22 is configured to inputvarious commands or instructions by touching the surface of the touchpanel with a finger, a stylus pen, or the like just as a user touchesthe display surface of the display unit 21.

The user executes touch operations of inputting various commands orinstructions by touching the surface of the touch panel. For example,the user can touch the surface of the touch panel at one point with thetip of a single finger, the tip of a single stylus pen, or the like andimmediately detaches his or her finger or the stylus pen.

Moreover, the user can execute the touch operation of touching thesurface of the touch panel with the tip of a single finger, the tip of asingle stylus pen, or the like, immediately executing an operationrapidly in an arbitrary direction from the touch position, and thendetaching his or her finger or the stylus from the surface of the touchpanel.

Moreover, the user can execute the touch operation by touching thesurface of the touch panel with the tip of a single finger, the tip of asingle stylus pen, or the like and moving the finger or the stylus penin a desired line such as a straight line or a circle in the touchedstate (that is, moving the tip of his or her finger or the like smoothlyon the surface).

In the following description, in particular, a tap operation is a touchoperation of touching nearly a single point of the surface of the touchpanel with the tip of a single finger, the tip of a single stylus pen,or the like and immediately detaching his or her finger or the styluspen from the surface of the touch panel.

For example, the tap operation is an operation that is executed on theoperation image or the electronic book image displayed on the displayunit 21 to instruct an instruction item such as an icon or a buttondisposed in the operation image or the electronic book image.

In the following description, in particular, a flick operation is atouch operation of touching the surface of the touch panel with the tipof a single finger, the tip of a single stylus pen, or the like,immediately detaching his or her finger, the stylus pen, or the likefrom the surface of the touch panel, and executing an operation rapidlyin an arbitrary direction from the touch position.

For example, the flick operation is an operation that is executed tochange over a page of an electronic book image displayed on the displayunit 21, as if turning a page of a book, and is executed to change(scroll) a display range when the entirety of the electronic book imagecorresponding to one page may not be displayed on the display unit 21.

In the following description, in particular, a slide operation is atouch operation of touching the surface of the touch panel with the tipof a single finger, the tip of a single stylus pen, or the like andmoving his or her finger, the stylus pen, or the like in a desired linesuch as a circle in the touched state.

For example, the slide operation is an operation that is executed toinstruct selection of a desired part in the text of an electronic bookimage displayed on the display unit 21.

In the following description, when the tap operation, the flickoperation, and the slide operation may not particularly be distinguishedfrom each other, these operations are simply referred to as a touchoperation.

The operation unit 22 detects the touch position of the tip of his orher finger, the tip of a stylus pen, or the like as the coordinates ofthe pixel position on the display surface of the display unit 21 at aconstant time interval such as a few [μsec], which is very short betweenthe start and the end of the touch operation, when the user touches thesurface of the touch panel.

At this time, the operation unit 22 detects the touch position as thecoordinates (that is, two dimensional coordinates) of the pixel positionexpressed on the assumption that an x axis is parallel to the verticaldirection of the display surface and a y axis is parallel to thehorizontal direction of the display surface. In the followingdescription, the vertical direction of the display surface is alsoreferred to as a display surface vertical direction and the horizontaldirection of the display surface is also referred to as a displaysurface horizontal direction.

The operation unit 22 transmits touch position information indicatingthe detected touch position to the control unit 20 whenever theoperation unit 22 detects the touch position.

When the control unit 20 receives the touch position information fromthe operation unit 22, for example, the control unit 20 detects a timeof receiving the touch position information as a time (hereinafter, alsoreferred to as a touch operation time) in which the touch operation isexecuted from the start to the end of the touch operation.

For example, the control unit 20 detects a displacement amount of touchposition indicated by the touch position information while the touchinformation is given, as a touch position displacement amount indicatinghow much the touch position is displayed from the start to the end ofthe touch operation.

The control unit 20 determines which touch operation is executed basedon the touch operation time and the touch position displacement amount.That is, the control unit 20 determines whether the touch operationexecuted at this time is the tap operation of touching nearly one pointwith the tip of a finger or the like and detaching the finger or thelike within a predetermined very short time.

The control unit 20 also determines whether the touch operation executedat this time is the flick operation of moving the tip of a finger or thelike only by a very short distance and detaching the finger or the likewithin a predetermined very short time or is the slide operation ofmoving the tip of a finger or the like for a predetermined time or moreor by a predetermined distance or more and detaching the finger or thelike.

When the control unit 20 determines that the touch operation executed atthis time is the tap operation, the control unit 20 determines aninstruction item instructed through the tap operation in an image beingdisplayed on the display unit 21 based on the touch position of the tapoperation.

The control unit 20 detects a command which can be assigned in advanceto the instruction item (that is, the determined instruction time)instructed through the tap operation and perform processing in responseto the detected command.

When the control unit 20 determines that the touch operation executed atthis time is the flick operation or the slide operation, as describedbelow, the control unit 20 performs processing in response to the flickoperation or the slide operation.

Thus, the control unit 20 performs various kinds of processingcorresponding to a key operation or a touch operation in response tothis key operation of the operation key of the operation unit 22 or thistouch operation of the touch panel of the operation unit 22.

In effect, when the control unit 20 receives a request for acquiring adesired electronic book through the key operation or the tap operation,the control unit 20 transmits acquisition request data used to make therequest for acquiring this electronic book from the transmission unit 23to the information sharing apparatus 14, the electronic book supplyapparatus, or the information supply apparatus via the network 13.

As a consequence, when the reception unit 24 receives the transmittedelectronic book data of the electronic book asked from the informationsharing apparatus 14, the electronic book supply apparatus, or theinformation supply apparatus, the control unit 20 transmits the receivedelectronic book data to the storage unit 25 to store the electronic bookdata.

When the control unit 20 acquires a home page, a report, or the likepublicized on the network 13 from the information supply apparatus, thecontrol unit 20 displays the home page, the report, or the like on thedisplay unit 21 without storing the home page, the report, or the likein the storage unit 25.

At this time, the control unit 20 can allow the user to execute apredetermined operation of selecting a part of interest in the text ofthe home page, the report, or the like by scrap or the like, in a statewhere the home page, the report, or the like is displayed.

Moreover, the control unit 20 may store the selected part as theelectronic book data of the electronic book in the storage unit 25, whenthe user selects the part of the text of the home page, the report, orthe like.

Thus, the control unit 20 can acquire a plurality of electronic bookdata from the external information sharing apparatus 14, the electronicbook supply apparatus, or the information supply apparatus and store theplurality of electronic book data in the storage unit 25.

When the user operates the key operation or the tap operation to selectan electronic book to be displayed and gives a request for displayingthis electronic book, the control unit 20 reads the electronic book dataof the electronic book selected from the storage unit 25 and transmitsthe electronic book data to the display control unit 26.

At this time, the display control unit 26 generates an electronic bookimage data corresponding to one page based on the electronic book data.For example, the display control unit 26 transmits at least a part ofthe electronic book image data as data of a display image to the displayunit 21 in accordance with the size or resolution of the display surfaceof the display unit 21.

Thus, as shown in FIG. 4, the display control unit 26 displays at leasta part of an electronic book image 27, which includes a one-page text (aphoto image or an illustration image displayed together with a one-pagetext) which is based on the electronic book image data, across theentire display surface of the display unit 21.

Moreover, the display control unit 26 displays at least a part of theelectronic book image 27 on the display surface of the display unit 21by setting the display surface vertical direction to be parallel to theimage vertical direction and the display surface horizontal direction tobe parallel to the image horizontal direction.

In the following description, between one end and the other end of theimage vertical direction parallel to the display surface verticaldirection in the electronic book image 27 (see FIG. 4), the one endindicated by an arrow a is also referred to as an image upper side andthe other end opposite to the one end indicated by the arrow a is alsoreferred to as an image lower side.

In the following description, between one end and the other end of theimage horizontal direction parallel to the display surface horizontaldirection in the electronic book image 27 (see FIG. 4), the one endindicated by an arrow b is also referred to as an image right side andthe other end opposite to the one end indicated by the arrow b is alsoreferred to as an image left side.

When the electronic book data is generated intentionally to display ahorizontally written text, as shown in FIG. 4, the horizontally writtentext of the electronic book image 27 is displayed on the display surfaceof the display unit 21 so that the individual rows of the text areparallel to the image horizontal direction.

In the case where the text is horizontally written, for example,characters located at the same position from the left side of the imagein the respective lines can be aligned as a column parallel to the imagevertical direction.

When the electronic book data is generated intentionally to display avertically written text, the vertically written text of the electronicbook image 27 is displayed on the display surface of the display unit 21so that the individual lines of the text are parallel to the imagevertical direction.

In the case where the text is vertically written, for example,characters located at the same position from the upper side of the imagein the respective lines can be aligned as a column parallel to the imagehorizontal direction.

In the following description, irrespective of the horizontally writtentext and the vertically written text, the beginning side of the text inthe electronic book image 27 is simply referred to as a front side andthe finishing side of the text is simply referred to as a rear side.

When the user operates a touch operation in the state where theelectronic book image 27 is displayed and the control unit 20 determinesthat the touch operation is the flick operation, the control unit 20detects a displacement direction (hereinafter, also referred to as atouch position displacement direction) of the touch position through theflick operation.

The control unit 20 controls the display control unit 26 so as to newlychange over the display of the electronic book image 27, when thedetected touch position displacement direction is a direction to bedisplaced from the image right side to the image left side or is adirection to be displaced from the image left side to the image rightside.

At this time, the display control unit 26 generates new electronic bookimage data based on the electronic book data in the touch positiondisplacement direction and transmits the generated electronic book imagedata to the display unit 21.

Thus, the display control unit 26 newly changes over the electronic bookimage 27 being currently displayed on the display unit 21 to display theelectronic book image one page before or one page after in the touchposition displacement direction.

In this way, the display control unit 26 newly changes over theelectronic book images 27 displayed on the display unit 21, as if thepages of the book were sequentially turned, in response to the flickoperation on the touch panel.

The control unit 20 controls the display control unit 26 to change thedisplay range of the electronic book image 27, when the detected touchposition displacement direction is a direction to be displaced from theimage upper side to the image lower side or is a direction to bedisplaced from the image lower side to the image upper side.

At this time, the display control unit 26 changes the transmitted partof the electronic book image data transmitted to the display unit 21into a part thereof to be transmitted to the display unit 21 in responseto the displacement direction of the touch position.

Thus, the display control unit 26 changes the display range of theelectronic book image 27 by scrolling the electronic book image 27displayed on the display unit 21 toward the lower side of the image orthe upper side of the image.

In this way, the display control unit 26 can change the display range ofthe electronic book image 27 in response to the flick operation on thetouch panel, even when the entire one-page electronic book image 27 maynot be displayed across the entire display surface of the display unit21.

2-2-1. Emphasis Display Process

Next, an emphasis display process of registering and displaying adesired part selected in the text of the electronic book by the user inan emphasis manner will be described.

The control unit 20 can instruct a desired part of the text, even whenthe user executes the slide operation on the surface of the touch panelwith the tip of his or her finger by using one of various smoothoperations in the state where the electronic book image 27 is displayedon the display unit 21.

As shown in FIG. 5, for example, the user can execute the slideoperation to instruct a desired part of the text with the tip of his orher finger or the like by tracing the desired part of the text in asubstantially straight line shape to instruct the desired part of thetext.

As shown in FIG. 6, for example, the user can execute the slideoperation to instruct the desired part of the text with the tip of hisor her finger or the like by tracing the desired part of the text in awavy shape to instruct the desired part of the text.

As shown in FIG. 7, for example, the user can execute the slideoperation to instruct a desired part of the text with the tip of his orher finger or the like by drawing a pair of parentheses on the desiredpart of the text to instruct the desired part of the text.

As shown in FIGS. 8A and 8B, for example, the user can execute the slideoperations to instruct the desired part of the text with the tip of hisor her finger or the like by drawing a line of a desired shape such as arectangular shape or a circular shape surrounding the desired part ofthe text to instruct the desired part of the text.

However, even when the user executes the slide operation in accordancewith any method in the state where the electronic book image 27 isdisplayed on the display unit 21, the user may not instruct the desiredpart of the text by using a method of holding the information displayterminal 11 or his or her dominant hand at the time of operating theslide operation.

For example, when the user executes the slide operation to trace thedesired part of the text in the substantially straight line shape withhis or her finger or the like, the user may trace the desired partobliquely with respect to the line direction of the plurality ofcharacters of the desired part or in an arched shape and thus may tracea part deviated from the desired part.

Moreover, when the user executes the slide operation to trace thedesired part of the text in the wavy shape, the user may trace a partdeviated from the desired part due to a variation in the height of thewavy shape during the slide operation or may trace a part graduallydeviated from the desired part.

As a consequence, when the user executes the slide operation to tracethe desired part of the text with the tip of his or her finger or thelike in a nearly straight line shape or a nearly wavy shape, the usermay instruct a part other than the desired part of the text due totouching of the tip of his or her finger or the like to a line adjacentto the desired part in the upper or lower direction of the image.

When the user executes the slide operation to trace the desired part ofthe text with the tip of his or her finger or the like in a nearlystraight line shape or a nearly wavy shape, for example, the user maytrace both the desired part and a part before or after the desired partdue to the fact that the user may not view the characters due to shadowof his or her finger or the like. In this case, the user instructs boththe desired part and the part other than the desired part of the text.

For example, when the user does not view the characters due to theshading of his or her finger or the like, the user may trace a partbetween the head and the tail of the desired part and thus may actuallyinstruct the part shorter than the desired part.

When the user executes the slide operation to parenthesize the desiredpart of the text with his or her finger or the like, the user mayparenthesize a part before or after the desired part and may thusinstruct both the desired part and the part other than the desired part.

Moreover, when the user executes the side operation to parenthesize thedesired part of the text, the user may parenthesize the desired part upto a line adjacent to the desired part in the upper or lower directionof the image and thus may instruct both the desired part and the line.

When the user executes the slide operation to parenthesize the desiredpart of the text, the user may parenthesize only a part between the headto the tail of the desired part and thus may actually instruct the partshorter than the desired part.

When the user executes the slide operation to surround the desired partof the text with his or her finger or the like, the user may surroundboth the desired part and a part before or after the desired part andthus may instruct both the desired part and the part other than thedesired part.

Moreover, when the user executes the slide operation to surround thedesired part of the text with his or her finger or the like, the usermay surround both the desired part and a line adjacent to the desiredpart in the upper or lower direction and thus may instruct both thedesired part and the line.

Furthermore, when the user executes the slide operation to surround thedesired part of the text with his or her finger or the like, the usermay surround only a part between the head and the tail of the desiredpart and thus may actually instruct the part shorter than the desiredpart.

Therefore, when the user instructs the desired part in the state wherethe electronic book image 27 is displayed, the control unit 20 controlsthe selection unit 28 to select a part estimated to be instructed forselection of the desired part from the text as an analysis target usedto specify the desired part. In the following description, the partestimated to be instructed for selection of the desired part from thetext is also referred to as an instruction estimated part.

In effect, when the control unit 20 determines whether the touchoperation executed on the surface of the touch panel is the slideoperation in the state where the electronic book image 27 is displayed,the control unit 20 detects whether the user operates the slideoperation again within a predetermined time selected in advance from thetime of this determination.

In the following description, a time at which it is determined that thetouch operation executed on the touch panel is the slide operation isreferred to as an operation determination time.

The predetermined time in which time measurement starts at the operationdetermination time is appropriately selected in advance by supposing atime necessary when the user executes the slide operation continuouslytwice and instructs to draw a pair of parentheses on the desired part ofthe text.

The control unit 20 determines that the slide operation has beenexecuted once to trace or surround the desired part of the text in theelectronic book image 27, when the slide operation is not executed againwithin the predetermined time from the operation determination time.

At this time, the control unit 20 detects the trajectory (hereinafter,also referred to as a touch trajectory) of the touch position displacedfrom the start to the end of the slide operation based on the touchposition information indicating the touch position detected during theone slide operation.

The control unit 20 determines which slide operation is executed (howthe tip of the finger or the like is moved in the slide operation) basedon the detected touch trajectory at this time.

That is, based on the touch trajectory, the control unit 20 determineswhether the slide operation performed at this time is the slideoperation of tracing the desired part of the text with the tip of thefinger or the like in a nearly straight line.

Based on the touch trajectory, the control unit 20 also determineswhether the slide operation executed at this time is the slide operationof tracing the desired part of the text with the tip of the finger orthe like in a wavy shape or is the slide operation of surrounding thedesired part of the text with the tip of the finger or the like.

The control unit 20 transmits, to the selection unit 28, both thedetermination result obtained by determining which slide operation isexecuted and touch position information indicating all of the touchpositions detected during the slide operation (that is, from the startto the end of the slide operation).

At this time, the control unit 20 extracts book attribute data from theelectronic book data read from the storage unit 25. Moreover, thecontrol unit 20 asks the display control unit 26 for a page number ofthe one-page text data used to generate the electronic book image datafor display.

The control unit 20 also extracts text data (which is one-page text dataand is, also referred to as display use text data below) of the pagenumber given from the display control unit 26 among the text data foreach page included in the electronic book data from the electronic bookdata.

Moreover, the control unit 20 acquires, from the display control unit26, display region information which indicates that a display region ofeach character (that is, each character within the display range) beingcurrently displayed is expressed by the coordinates of the pixelposition on the display surface of the display unit 21.

That is, the control unit 20 acquires the display region informationregarding each character of the entire text from the display controlunit 26, when the entirety of the one-page text is displayed.

The control unit 20 acquires the display region information regardingeach character of a part of the text from the display control unit 26,when only the part of the one-page text is displayed. Thus, the controlunit 20 allows the display region information regarding the individualcharacters to correspond to the characters within the display range inthe display use text data.

The control unit 20 also transmits the display use text data(hereinafter, also referred to as region correspondence text data) ofthe one-page text, in which the display region information is made tocorrespond to the characters within the display range, and the bookattribute data to the selection unit 28.

On the other hand, when the control unit 20 determines that the touchoperation is the slide operation within the predetermined time from theoperation determination time (executes the slide operation again), thecontrol unit 20 determines that the slide operation performed at thistime is the slide operation of parenthesizing the desired part of thetext.

The control unit 20 transmits, to the selection unit 28, thedetermination result obtained by determining which slide operation isexecuted at this time and the touch position information indicating allof the touch positions detected during each of the slide operationsexecuted twice (from the start to the end of each slide operation).

The control unit 20 prepares the book attribute data and generates theregion correspondence text data, as described above. Then, the controlunit 20 also transmits the region correspondence text data and the bookattribute data to the selection unit 28.

When the selection unit 28 receives the determination result obtained bydetermining which slide operation is executed, the touch positioninformation, the region correspondence text data, and the book attributedata from the control unit 20, the selection unit 28 performs a rangedetection process to detect an instruction range instructed in the textbeing displayed.

Hereinafter, a case will be described in which horizontally writtensentences are displayed as a text of the electronic book image 27 on thedisplay surface of the display unit 21, as in the description made withreference to FIG. 4.

As shown in FIG. 9, the selection unit 28 specifies a touch position SP1at the start time of the slide operation and a touch position EP1 at theend time of the slide operation based on the touch position information,when the user execute the slide operation to trace the desired part ofthe text in a straight line.

In the following description, the touch position SP1 at the start timeof the slide operation is also referred to as an operation start touchposition SP1 and the touch position EP1 at the end time of the slideoperation is also referred to as an operation termination touch positionEP1.

The selection unit 28 determines whether the specific operation starttouch position SP1 and the specific operation termination touch positionEP1 are located on one straight line (hereinafter, referred to as ahorizontal straight line) parallel to the image horizontal direction.

As a consequence, when the operation start touch position SP1 and theoperation termination touch position EP1 are not located on the onehorizontal straight line, the selection unit 28 sets the operation starttouch position SP1 and the operation termination touch position EP1 asone and the other vertexes of one diagonal line of a rectangle.

The selection unit 28 detects an intersection point CP1 between astraight line passing through the operation start touch position SP1 andparallel to the image vertical direction and a straight line passingthrough the operation termination touch position EP1 and parallel to theimage horizontal direction.

Moreover, the selection unit 28 also detects an intersection point CP2between a straight line passing through the operation start touchposition SP1 and parallel to the image horizontal direction and astraight line passing through the operation termination touch positionEP1 and parallel to the image vertical direction.

The selection unit 28 sets the two detected intersection points CP1 andCP2 as the two remaining vertexes of the rectangle. Then, the selectionunit 28 detects, as an instruction range DA1, the range of the rectanglewhich has the operation start touch position SP1, the operationtermination touch position EP1, and the two intersection points CP1 andCP2 within the display range of the electronic book image 27.

When an operation start touch point SP2 and an operation terminationtouch position EP2 are located on one horizontal straight line, as shownin FIG. 10, the selection unit 28 detects the upper and lower ends ofthe display region of the characters on which the display position islocated on this horizontal straight line.

The selection unit 28 detects two intersection points CP3 and CP4between a straight line passing through the operation start touchposition SP2 and parallel to the image vertical direction and a straightline passing though the detected upper and lower ends and parallel tothe image horizontal direction.

The selection unit 28 also detects two intersection points CP5 and CP6between a straight line passing through an operation termination touchposition EP2 and parallel to the image vertical direction and a straightline passing through the detected upper and lower ends and parallel tothe image horizontal direction.

Then, the selection unit 28 sets the detected four intersection pointsCP3 to CP6 as four vertexes of the rectangle. Thus, the selection unit28 detects, as an instruction range DA2, the range of the rectanglewhich has the detected four intersection points CP3 to CP6 as the fourvertexes within the display range of the electronic book image 27.

When the user executes the slide operation to trace the desired part ofthe text in a wavy shape, as shown in FIG. 11, the selection unit 28specifies an operation start touch position SP3 and an operationtermination touch position EP3 of the slide operation based on the touchposition information.

Based on the touch position information, the selection unit 28 alsospecifies a touch position HP1 closest to (in this case, the uppermostside of an image) the line of the beginning side of the text beingdisplayed among a plurality of touch positions.

Based on the touch position information, the selection unit 28 alsospecifies a touch position FP1 closest to (in this case, the lowermostside of the image) the line of the finishing side of the text in theelectronic book image 27 among the plurality of touch positions.

In the following description, the touch position HP1 closest to the lineof the beginning side of the text being displayed is also referred to asa beginning touch position HP1 and the touch position FP1 closest to theline of the finishing side of the text being displayed is also referredto as a finishing touch position FP1.

The selection unit 28 also detects an intersection point CP7 between astraight line passing through the operation start touch position SP3 andparallel to the image vertical direction and a straight line passingthrough the beginning touch position HP1 and parallel to the imagehorizontal direction.

The selection unit 28 also detects an intersection point CP8 between astraight line passing through the operation start touch position SP3 andparallel to the image vertical direction and a straight line passingthrough the finishing touch position FP1 and parallel to the imagehorizontal direction.

The selection unit 28 also detects an intersection point CP9 between astraight line passing through the operation termination touch positionEP3 and parallel to the image vertical direction and a straight linepassing through the beginning touch position HP1 and parallel to theimage horizontal direction.

The selection unit 28 also detects an intersection point CP10 between astraight line passing through the operation termination touch positionEP3 and parallel to the image vertical direction and a straight linepassing through the finishing touch position FP1 and parallel to theimage horizontal direction.

Then, the selection unit 28 sets the detected four intersection pointsCP7 to CP10 as the four vertexes of the rectangle. Thus, the selectionunit 28 detects, as an instruction range DA3, the range of the rectanglewhich has the detected four intersection points CP7 to CP10 as the fourvertexes within the display range of the electronic book image 27.

When the user executes the slide operation twice to draw a pair ofparentheses on the desired part of the text, as shown in FIG. 12, theselection unit 28 specifies an operation start touch position SP4 of thefirst slide operation based on the touch position information obtainedthrough the first slide operation.

The selection unit 28 also specifies an operation termination touchposition EP4 of the first slide operation based on the touch positioninformation obtained through the first slide operation.

The selection unit 28 also specifies an operation start touch positionSP5 and an operation termination touch position EP5 of the second slideoperation based on the touch position information obtained through thesecond slide operation.

The selection unit 28 also detects one position (in this case, theoperation termination touch position EP4 located on the left upper sideof the image), which is located on the beginning side of the text beingdisplayed, between the operation start touch position SP4 and theoperation termination touch position EP4 of the first slide operation.

The selection unit 28 also detects one position (in this case, theoperation termination touch position EP5 located on the right lower sideof the image), which is located on the finishing side of the text beingdisplayed, between the operation start touch position SP5 and theoperation termination touch position EP5 of the second slide operation.

Then, the selection unit 28 sets the operation start touch position SP4detected on the beginning side of the text and the operation terminationtouch position EP5 detected on the finishing side of the text as twovertexes which are one end and the other end of one diagonal line of therectangle.

The selection unit 28 also detects an intersection point CP11 between astraight line passing through the operation start touch position SP4detected on the beginning side of the text and parallel to the imagevertical direction and a straight line passing through the operationtermination touch position EP5 detected on the finishing side of thetext and parallel to the image horizontal direction.

The selection unit 28 also detects an intersection point CP12 between astraight line passing through the operation start touch position SP4detected on the beginning side of the text and parallel to the imagehorizontal direction and a straight line passing through the operationtermination touch position EP5 detected on the finishing side of thetext and parallel to the image vertical direction.

Then, the selection unit 28 sets the two detected intersection pointsCP11 and CP12 as the two remaining vertexes of the rectangle. Thus, theselection unit 28 detects, as an instruction range DA4, the range of therectangle which has the operation start touch position SP4 on thebeginning side of the text, the operation termination touch position EP5on the finishing side of the text, and the two intersection points CP11and CP12 as the four vertexes within the display range of the electronicbook image 27.

When the user executes the slide operation to surround the desired partof the text, as shown in FIGS. 13A and 13B, the selection unit 28specifies operation start touch positions SP6 and SP7 and operationtermination touch positions EP6 and EP7 based on the touch positioninformation.

For example, the selection unit 28 detects the touch trajectories fromthe operation start touch positions SP6 and SP7 to the operationtermination touch positions EP6 and EP7, respectively. Thus, theselection unit 28 detects the ranges surrounded by the touchtrajectories as instruction ranges DA5 and DA6 in the display range ofthe electronic book image 27.

When the selection unit 28 detects the instruction ranges DA1 to DA6 inresponse to the kinds of slide operations, the selection unit 28continues performing a selection process of selecting the instructionestimated part from the text in the electronic book image 27 beingdisplayed, based on the instruction ranges DA1 to DA6.

As a method of selecting the selection process, for example, there arethree kinds of first to third selection methods. A first selectionmethod is an effective method of narrowing the instruction ranges DA1 toDA6 and selecting the instruction estimated part, for example, when theuser tends to instruct the desired part of the text and the part beforeand after the desired part.

A second selection method is an effective method of enlarging theinstruction ranges DA1 to DA6 and selecting the instruction estimatedpart, for example, when the user tends to instruct only a part betweenthe head and the tail of the desired part of the text.

A third selection method is an effective method of selecting theinstruction estimated part from the instruction range DA1 to DA6 inconsideration of a variation in the desired part of the text, when theuser tends to variably instruct a part larger than the desired part ofthe text or a part narrower than the desired part of the text.

Accordingly, for example, the control unit 20 allows the user in advanceto select one of the first to third selection methods to select theinstruction estimated part from the text and execute the selectionprocess and sets the selected method.

Hereinafter, the selection process performed in accordance with thefirst to third selection methods executed by the selection unit 28 basedon the setting details of the selection method will sequentially bedescribed.

First, the selection process performed in accordance with the firstselection method will be described. When the selection process is set tobe performed in accordance with the first selection method, theselection unit 28 detects the characters within the instruction rangesDA1 to DA6 based on the instruction ranges DA1 to DA6 detectedpreviously and the region correspondence text data.

At this time, for example, the selection unit 28 detects characters(hereinafter, also referred to as in-range characters), of which thedisplay region completely enters the instruction ranges DA1 to DA6, asthe characters within the instruction ranges DA1 to DA6.

For example, the selection unit 28 detects characters (hereinafter, alsoreferred to as edge characters), of which the display region is locatedon the edge of the instruction ranges DA1 to DA6, as characters withinthe instruction ranges DA1 to DA6.

That is, when the in-range characters are present and no edge charactersare present, as shown in FIGS. 14A and 14B, the selection unit 28detects only the in-range characters as the characters within theinstruction range DA1.

When the in-range characters are present and the edge characters arepresent, the selection unit 28 detects both the in-range characters andthe edge characters as the characters within the instruction range DA6.

The selection unit 28 detects one line (in this case, one line close tothe upper side of the image) closest to the beginning side and one line(in this case, one line close to the lower side of the image) closest tothe finishing side among the lines of the characters within theinstruction ranges DA1 to DA6.

When the characters are located in only one line within the instructionrange DA1, the selection unit 28 (see FIG. 14A) detects both one lineclosest to the beginning side and one line closest to the finishingside.

The selection unit 28 detects one row (in this case, one row close tothe leftmost side of the image) closest to the front side of the rowwith the maximum number of characters and one column (in this case, onecolumn close to rightmost side of the image) closest to the finishingside of the row with the maximum number of characters among the lines ofthe characters within the instruction ranges DA1 to DA6.

Moreover, the selection unit 28 (see FIGS. 14A and 14B) detects onecharacter located at the intersection point between one row L1 or L3closest to the beginning side and one column C1 or C3 closest to thefront side of the row with the maximum number of characters, as areference point BP1 or BP3 from which the front character of theinstruction estimated part is started to be searched within the text.

In the following description, the reference points BP1 and BP3 fromwhich the front characters of the instruction estimated part aresearched within the text are also referred to as the front referencecharacters BP1 and BP3, respectively.

Moreover, the selection unit 28 (see FIGS. 14A and 14B) detects onecharacter located at the intersection point between one row L2 or L4closest to the finishing side and one column C2 or C4 closest to thefinishing side of the row with the maximum number of characters, as areference point BP2 or BP4 from which the rear character of theinstruction estimated part is searched within the text.

In the following description, the reference points BP2 and BP4 fromwhich the rear characters of the instruction estimated part are searchedwithin the text are also referred to as the rear reference charactersBP2 and BP4, respectively.

Thus, the selection unit 28 (see FIGS. 14A and 14B) sets the ranges fromthe front reference characters BP1 and BP3 to the rear referencecharacters BP2 and PB4 in the text of the display range, as searchranges SE1 and SE2 used to search the front and rear characters of theinstruction estimated part, respectively.

Here, as described above, the user instructs a desired word as thedesired part in the text of the display range. Moreover, the userinstructs a desired phrase, clause, or the like including two or morewords in some cases.

Accordingly, the selection unit 28 searches for characters indicatingseparations of a sentence, such as a period, a comma, and a blank, amongvarious characters within the search range SE1 or SE2 by using theregion correspondence text data. In the following description, thecharacters indicating separations of a sentence, such as a period, acomma, and a blank are also referred to as separation characters.

In effect, the selection unit 28 searches for the separation character,while sequentially determining the kinds of characters from the frontreference characters BP1 and BP3 to the rear reference characters BP2and BP4 within the search ranges SE1 and SE2, respectively, character bycharacter.

As a consequence, when the selection unit 28 detects one separationcharacter from the front reference characters BP1 and BP3 to the rearreference characters BP2 and BP4, respectively, the selection unit 28terminates the search for the separation character at the detection timein a direction from the front reference characters BP1 and BP3 and therear reference characters BP2 and BP4, respectively.

Likewise, the selection unit 28 searches for the separation character,while sequentially determining the kinds of characters from the rearreference characters BP2 and BP4 to the front reference characters BP1and BP3 within the search ranges SE1 and SE2, respectively, character bycharacter.

When the selection unit 28 detects one separation character from thefront reference characters BP1 and BP3 to the rear reference charactersBP2 and BP4, respectively, at this time, the selection unit 28 searchesfor the separation character in a direction from the rear referencecharacters BP2 and BP4 and the front reference characters BP1 and BP3,respectively.

As a consequence, when the selection unit 28 detects one separationcharacter from the rear reference characters BP2 and BP4 to the frontreference characters BP1 and BP3, respectively, the selection unit 28terminates the search for the separation character at the detection timein the direction from the rear reference characters BP2 and BP4 and thefront reference characters BP1 and BP3, respectively.

Then, when the selection unit 28 detects the separation character withinthe search ranges SE1 and SE2, the selection unit 28 compares thedisplay position of the separation character detected from the frontreference characters BP1 and BP3 to the display position of theseparation character detected from the rear reference characters BP2 andBP4.

In the following description, one separation character searched anddetected from the front reference characters BP1 and BP3 is alsoreferred to as a front separation character and one separation charactersearched and detected from the rear reference characters BP2 and BP4 isalso referred to as a rear separation character.

As a consequence, the selection unit 28 sets, as the instructionestimated part, the character string within the range from the frontseparation character to the rear separation character, when the displayposition of the front separation character is different from the displayposition of the rear separation character (that is, the front separationcharacter is closer to the beginning side than the rear separationcharacter).

That is, the selection unit 28 detects the front separation characterand the rear separation character as the front and rear characters ofthe instruction estimated part from the text of the display range andselects a phrase, a clause, or the like of the range from the frontseparation character to the rear separation character as the instructionestimated part.

On the other hand, the selection unit 28 sets, as the instructionestimated part, a character string of the range from the front referencecharacters BP1 and BP3 to the rear reference characters BP2 and BP4,when the display position of the front separation character accords withthe display position of the rear separation character, and the frontseparation character and the rear separation character are the sameseparation characters at the same position.

That is, the selection unit 28 detects the front reference charactersBP1 and BP3 and the rear reference characters BP2 and BP4 as the frontand rear characters of the instruction estimated part from the text ofthe display range.

The selection unit 28 selects, as the instruction estimated part, forexample, a predetermined part or the like within one word, oneseparation, or the like of the range from the front reference charactersBP1 and BP3 to the rear reference characters BP2 and BP4 from the textof the display range.

When the selection unit 28 does not detect the front separationcharacter in the searching from the front reference characters BP1 andBP3 to the rear reference characters BP2 and BP4, the selection unit 28also sets, as the instruction estimated part, the character string ofthe range from the front reference characters BP1 and BP3 to the rearreference characters BP2 and BP4.

That is, the selection unit 28 also detects the front referencecharacters BP1 and BP3 and the rear reference characters BP2 and BP4 asthe front and rear characters of the instruction estimated part from thetext of the display range.

The selection unit 28 selects, as the instruction estimated part, forexample, a predetermined part or the like within one word, oneseparation, or the like of the range from the front reference charactersBP1 and BP3 to the rear reference characters BP2 and BP4 from the textof the display range.

Thus, the selection unit 28 can select, as the instruction estimatedpart, the part estimated to be instructed by the user very accurately asthe instruction estimated part from the text of the display range, evenwhen the user tends to instruct the desired part of the text and thepart before and after the desired part.

Next, the selection process performed in accordance with the secondselection method will be described. When the selection process is set tobe performed in accordance with the second selection method, theselection unit 28 detects the characters within the instruction rangesDA1 to DA6, as in the first selection method described above.

As in the first selection method described above, the selection unit 28detects one row closest to the beginning side, one row closest to thefinishing side, one column closest to the front side of the row with themaximum number of characters, and one column closest to the finishingside of the row with the maximum number of characters among the lines ofthe characters within the instruction ranges DA1 to DA6.

As in the first selection method described above, the selection unit 28detects the front reference characters BP1 and BP3 and the rearreference characters BP2 and BP4 based on the detection results,respectively.

At this time, the selection unit 28 sets the characters of the frontreference characters BP1 and BP3 in the text of the display range to thefront character in the display range as search ranges (hereinafter, alsoreferred to as beginning search ranges) SE3 and SE5 used to search thefront character of the instruction estimated part.

Moreover, the selection unit 28 sets the rear reference characters BP2and BP4 in the text of the display range to the rear character in thedisplay range as search ranges (hereinafter, also referred to asfinishing search ranges) SE4 and SE6 used to search for the rearcharacter of the instruction estimated part.

The selection unit 28 searches for the separation character, whilesequentially determining the kinds of characters from the frontreference characters BP1 and BP3 in the beginning search ranges SE3 andSE5 to the front characters of the display ranges, respectively,character by character by using the region correspondence text data.

As a consequence, when the selection unit 28 detects one separationcharacter from the front reference characters BP1 and BP3 to the frontcharacters of the display range, respectively, the selection unit 28terminates the search for the separation character at the detection timein a direction from the front reference characters BP1 and BP3 and thefront characters of the display range, respectively.

Moreover, the selection unit 28 searches for the separation character,while sequentially determining the kinds of characters from the rearreference characters BP2 and BP4 in the finishing search ranges SE4 andSE6 to the rear characters of the display ranges, respectively,character by character by using the region correspondence text data.

As a consequence, when the selection unit 28 detects one separationcharacter from the rear reference characters BP2 and BP4 to the rearcharacters of the display range, respectively, the selection unit 28terminates the search for the separation character at the detection timein the direction from the rear reference characters BP2 and BP4 and therear characters of the display range, respectively.

In the following description, a separation character searched anddetected from the front reference characters BP1 and BP3 is alsoreferred to as a front separation character and a separation charactersearched and detected from the rear reference characters BP2 and BP4 isalso referred to as a rear separation character.

Thus, the selection unit 28 sets, as the instruction estimated part, thecharacter string within the range from the front separation character tothe rear separation character, when the selection unit 28 detects thefront separation character and the rear separation character.

That is, the selection unit 28 detects the front separation characterand the rear separation character as the front and rear characters ofthe instruction estimated part from the text of the display range andselects a phrase, a clause, or the like of the range from the frontseparation character to the rear separation character as the instructionestimated part.

When the user selects the second selection method in advance and thefront separation character or the rear separation character may not bedetected within the display range, the control unit 20 permits selectingwhether the search range is changed and sets the change.

When the search range is changed, the control unit 20 permits selectingwhether the front reference characters BP1 and BP3 to the rear referencecharacters BP2 and BP4 is set as the search, range or the end of thesearch range is changed from the front and rear character of the displayrange to the front and rear character of one page.

However, when both of the front separation character and the rearseparation character may not be detected within the display range, thecontrol unit 20 applies the change in the search range to the search forboth of the front and rear characters of the instruction estimated part.

When the rear separation character can be detected within the displayrange and the front separation character may not be detected within thedisplay range, the control unit 20 applies the change in the searchrange to the search for only the front character of the instructionestimated part.

Moreover, when the front separation character can be detected within thedisplay range and the rear separation character may not be detectedwithin the display range, the control unit 20 applies the change in thesearch range to the search for only the rear character of theinstruction estimated part.

Accordingly, when the selection unit 28 does not detect the frontseparation character within the beginning search ranges SE3 and SE5, theselection unit 28 determines whether the search range is changed inaccordance with the previous setting details.

As a consequence, when the selection unit 28 does not detect the frontseparation character within the beginning search ranges SE3 and SE5 andthe search range is set not to be changed, the selection unit 28 setsthe front character of the display range as the front character of theinstruction estimated part.

When the selection unit 28 does not detect the front separationcharacter within the beginning search ranges SE3 and SE5 and the ends ofthe beginning search ranges SE3 and SE5 are set to be changed, theselection unit 28 determines whether the front character of the displayrange is the front character of one page including the display range.

As a consequence, when the front character of the current display rangeis the front character (that is, a predetermined range from the frontcharacter of one page is the display range currently) of one page; theselection unit 28 sets the front character of the display range as thefront character of the instruction estimated part.

On the other hand, when the front character of the current display rangeis different from the front character (that is, a predetermined rangeexcept for the front character of one page is the display rangecurrently) of one page, the selection unit 28 changes the ends of thebeginning search ranges SE3 and SE5 to the front character of one page.

At this time, the selection unit 28 searches for the front separationcharacter, while sequentially determining the kinds of characters fromthe character adjacent to the beginning side to the front character ofone page character by character in the front characters of the displayrange within a new front search range by using the region correspondencetext data. In the following description, the character adjacent to thefront character of the display range on the beginning side is alsoreferred to as a display range preceding character.

As a consequence, when the selection unit 28 detects one frontseparation character from the display range preceding character to thefront character of one page, the selection unit 28 terminates the searchfor the front separation character in a direction from the display rangepreceding character to the front character of one page at the detectiontime.

The selection unit 28 sets one front separation character detected fromthe display range preceding character to the front character of one page(that is, a new beginning search range) as the front character of theinstruction estimated character.

On the other hand, when the selection unit 28 detects no frontseparation character even in the search for the display range precedingcharacter to the front character of one page (that is, within the newbeginning search range), the selection unit 28 sets the front characterof one page as the front character of the instruction estimatedcharacter.

When the selection unit 28 detects no rear separation character withinthe finishing search ranges SE4 and SE6, the selection unit 28determines whether the search range is changed in accordance with theprevious setting details.

As a consequence, when the selection unit 28 detects no rear separationcharacter within the finishing search ranges SE4 and SE6 but the searchrange is set not to be changed, the selection unit 28 sets the rearcharacter of the display range as the rear character of the instructionestimated part.

Moreover, when the selection unit 28 detects no rear separationcharacter within the finishing search ranges SE4 and SE6 and the ends ofthe finishing search ranges SE4 and SE6 are set to be changed, theselection unit 28 determines whether the rear character of the displayrange is the rear character of one page including the display range.

As a consequence, when the rear character of the current display rangeis the rear character of one page (that is, a predetermined range on thebeginning side from the rear character of one page is the displayrange), the selection unit 28 sets the rear character of the displayrange as the rear character of the instruction estimated part.

On the other hand, when the rear character of the current display rangeis different from the rear character of one page (that is, thepredetermined range except for the rear character of one page is thedisplay range), the selection unit 28 changes the ends of the finishingsearch ranges SE4 and SE6 to the rear character of one page.

At this time, the selection unit 28 searches for the rear separationcharacter, while sequentially determining the kinds of characters fromthe character adjacent to the finishing side to the rear character ofone page character by character in the rear characters of the displayrange within a new finishing search range by using the regioncorrespondence text data. In the following description, the characteradjacent to the rear character of the display range on the finishingside is also referred to as a display range subsequent character.

As a consequence, when the selection unit 28 detects one rear separationcharacter from the display range subsequent character to the rearcharacter of one page, the selection unit 28 terminates the search forthe rear separation character in a direction from the display rangesubsequent character to the rear character of one page at the detectiontime.

The selection unit 28 sets one rear separation character detected fromthe display range subsequent character to the rear character of one page(that is, a new finishing search range) as the rear character of theinstruction estimated character.

On the other hand, when the selection unit 28 detects no rear separationcharacter even in the search for the display range subsequent characterto the rear character of one page (that is, within the new finishingsearch range), the selection unit 28 sets the rear character of one pageas the rear character of the instruction estimated character.

Thus, the selection unit 28 appropriately detects, as the frontcharacter of the instruction estimated part, the front separationcharacter, the front character of the display range, and the frontcharacter of one page from the text of the display range or one page.

Moreover, the selection unit 28 appropriately detects, as the rearcharacter of the instruction estimated part, the rear separationcharacter, the front character of the display range, and the rearcharacter of one page from the text of the display range or one page.Then, the selection unit 28 selects, as the instruction estimated part,the phrase, the clause, or the like of the range from the detected frontcharacter to the detected rear character from the text of the displayrange or one page.

When the selection unit 28 does not detect the front separationcharacter within the beginning search ranges SE3 and SE5 and the frontreference characters BP1 and BP3 to the rear reference characters BP2and BP4 are set as the search ranges, the selection unit 28 searches forthe front separation character, as in the first selection methoddescribed above.

That is, the selection unit 28 searches for the front separationcharacter, while sequentially determining the kinds of characters fromthe front reference characters BP1 and BP3 to the rear referencecharacters BP2 and BP4 character by character within the search range byusing the region correspondence text data.

As a consequence, when the selection unit 28 detects one frontseparation character from the front reference characters BP1 and BP3 tothe rear reference characters BP2 and BP4, the selection unit 28terminates the search for the front separation character at thedetection time.

Moreover, when the selection unit 28 searches for the rear separationcharacter, while sequentially determining the kinds of characters fromthe rear reference characters BP2 and BP4 to the rear character of thedisplay range or one page character by character, as described above.

At this time, when the selection unit 28 detects the rear character ofthe instruction estimated part from the rear reference characters BP2and BP4 to the rear character of the display range or one page, asdescribed above, the selection unit 28 sets the front separationcharacter as the front character of the instruction estimated part.

On the other hand, when the selection unit 28 detects no frontseparation character even in the searching from the front referencecharacters BP1 and BP3 to the rear reference characters BP2 and BP4(that is, within the search range), the selection unit 28 terminates thesearch for the front separation character at the detection time.

At this time, when the selection unit 28 detects the rear character ofthe instruction estimated part from the rear reference characters BP2and BP4 to the rear character of the display range or one page, theselection unit 28 sets the front reference characters BP1 and BP3 as thefront character of the instruction estimated part.

Moreover, when the selection unit 28 detects no rear separationcharacter within the finishing search ranges SE4 and SE6 and the rearreference characters BP1 and BP3 to the rear reference characters BP2and BP4 are set as the search range, respectively, the selection unit 28searches for the rear separation character, as in the first selectionmethod described above.

That is, the selection unit 28 searches for the rear separationcharacter, while sequentially determining the kinds of characters fromthe rear reference characters BP2 and BP4 to the front referencecharacters BP1 and BP3 character by character within the search range byusing the region correspondence text data.

As a consequence, when the selection unit 28 detects one rear separationcharacter from the rear reference characters BP2 and BP4 to the frontreference characters BP1 and BP3, the selection unit 28 terminates thesearch for the rear separation character at the detection time.

At this time, when the selection unit 28 detects the front character ofthe instruction estimated part from the front reference characters BP1and BP3 to the front character of the display range or one page, asdescribed above, the selection unit 28 sets the rear separationcharacter as the rear character of the instruction estimated character.

On the other hand, when the selection unit 28 detects the frontseparation character from the front reference characters BP1 and BP3 tothe rear reference characters BP2 and BP4, the selection unit 28compares the display position of the front separation character to thedisplay position of the rear separation character, as in the firstselection method described above.

As a consequence, the selection unit 28 sets, as the instructionestimated part, the character string within the range from the frontseparation character to the rear separation character, when the displayposition of the front separation character is different from the displayposition of the rear separation character (that is, the front separationcharacter is closer to the beginning side than the rear separationcharacter).

That is, the selection unit 28 detects the front separation characterand the rear separation character as the front and rear characters ofthe instruction estimated part from the text of the display range andselects a phrase, a clause, or the like of the range from the frontseparation character to the rear separation character as the instructionestimated part.

On the other hand, the selection unit 28 sets, as the instructionestimated part, a character string of the range from the front referencecharacters BP1 and BP3 to the rear reference characters BP2 and BP4,when the display position of the front separation character accords withthe display position of the rear separation character and the frontseparation character and the rear separation character are the sameseparation characters at the same position.

That is, the selection unit 28 detects the front reference charactersBP1 and BP3 and the rear reference characters BP2 and BP4 as the frontand rear characters of the instruction estimated part from the text ofthe display range.

The selection unit 28 selects, as the instruction estimated part, forexample, a predetermined part or the like within one word, one phrase,or the like of the range from the front reference characters BP1 and BP3to the rear reference characters BP2 and BP4 from the text of thedisplay range.

When the selection unit 28 does not detect the rear separation charactereven in the searching from the rear reference characters BP2 and BP4 tothe front reference characters BP1 and BP3 (that is within the searchrange), the selection unit 28 also sets the rear reference charactersBP2 and BP4 as the rear character of the instruction estimated part.

That is, the selection unit 28 appropriately detects, as the frontcharacter of the instruction estimated part, the front separationcharacter, the front character of the display range, or the frontcharacter of one page from the text of the display range or one page anddetects the rear reference characters BP2 and BP4 as the rear characterof the instruction estimated part.

The selection unit 28 selects, as the instruction estimated part, aphrase, a clause, or the like of the range from the detected frontcharacter to the detected rear character from the text of the displayrange or one page.

Thus, the selection unit 28 can select, as the instruction estimatedpart, the part estimated to be instructed by the user very accuratelyfrom the text of the display range or one page, even when the user tendsto instruct only a part of the desired part of the text.

Next, the selection process performed in accordance with the thirdselection method will be described. When the selection process is set tobe performed in accordance with the third selection method, theselection unit 28 detects the characters within the instruction rangesDA1 to DA6, as in the first selection method described above.

As in the first selection method described above, the selection unit 28detects one row closest to the beginning side, one row closest to thefinishing side, one column closest to the front side of the row with themaximum number of characters, and one column closest to the rear side ofthe row with the maximum number of characters among the lines of thecharacters within the instruction ranges DA1 to DA6.

As in the first selection method described above, the selection unit 28detects the front reference characters BP1 and BP3 and the rearreference characters BP2 and BP4 based on the detection results,respectively.

Then, the selection unit 28 basically performs the same processing asthat of the first selection method described above. That is, theselection unit 28 sets the range from the front reference characters BP1and BP3 to the rear reference characters BP2 and BP4 as the searchranges SE1 and SE2, respectively, and searches for the front separationcharacter within search ranges SE1 and SE2.

At this time, when the selection unit 28 does not detect the frontseparation character even in the searching of the range from the frontreference characters BP1 and BP3 to the rear reference characters BP2and BP4, respectively, the selection unit 28 sets, as the instructionestimated part, a character string from the front reference charactersBP1 and BP3 to the rear reference characters BP2 and PB4.

That is, the selection unit 28 detects the front reference charactersBP1 and BP3 and the rear reference characters BP2 and BP4 as the frontand rear characters of the instruction estimated part from the text ofthe display range.

The selection unit 28 selects, as the instruction estimated part, forexample, a predetermined part or the like within one word, one phrase,or the like of the range from the front reference characters BP1 and BP3to the rear reference characters BP2 and BP4 from the text of thedisplay range.

Moreover, when the selection unit 28 detects one front separationcharacter from the front reference characters BP1 and BP3 to the rearreference characters BP2 and BP4, the selection unit 28 terminates thesearching of the front separation character at the detection time andcontinues searching for the rear separation character within the searchranges SE1 and SE2.

When the selection unit 28 detects one separation character from therear reference characters BP2 and BP4 to the front reference charactersBP1 and BP3, the selection unit 28 terminates the search for the rearseparation character at the detection time and compares the displayposition of the front separation character to the display position ofthe rear separation character.

As a consequence, the selection unit 28 sets, as the instructionestimated part, the character string within the range from the frontseparation character to the rear separation character, when the displayposition of the front separation character is different from the displayposition of the rear separation character at the same position.

That is, the selection unit 28 detects the front separation characterand the rear separation character as the front and rear characters ofthe instruction estimated part from the text of the display range andselects a phrase, a clause, or the like of the range from the frontseparation character to the rear separation character as the instructionestimated part.

On the other hand, the selection unit 28 basically continues performingthe same processing as that of the second selection method describedabove, when the display position of the front separation characteraccords with the display position of the rear separation character andthe front separation character and the rear separation character are thesame separation characters.

That is, the selection unit 28 sets, as the beginning search ranges SE3and SE5, the front reference characters BP1 and BP3 in the text of thedisplay range to the front character of the display range and sets therear reference characters BP2 and BP4 to the rear character of thedisplay range as the finishing search ranges SE4 and SE6.

Thus, when the selection unit 28 searches for the front separationcharacter within the beginning search ranges SE3 and SE5 and detects thefront separation character, the selection unit 28 terminates the searchfor the front separation character and searches for the rear separationcharacter within the finishing search ranges SE4 and SE6.

When the selection unit 28 detects the rear separation character, theselection unit 28 terminates the search for the rear separationcharacter at the detection time and sets, as the instruction estimatedpart, the character string of the range from the front separationcharacter to the rear separation character.

That is, the selection unit 28 detects the front separation characterand the rear separation character as the front and rear characters ofthe instruction estimated part from the text of the display range andselects a phrase, a clause, or the like of the range from the frontseparation character to the rear separation character as the instructionestimated part.

When the user selects the third selection method in advance and thefront separation character or the rear separation character may not bedetected within the display range, the control unit 20 permits selectingwhether the search range is changed and sets the change.

However, when the change in the search range is selected, the controlunit 20 automatically changes only the end of the search range from thefront and rear characters of the display range to the front and rearcharacters of one page and sets the change.

Moreover, when both of the front separation character and the rearseparation character are not be detected within the display range, thecontrol unit 20 applies the change in the search range to the search forboth of the front and rear characters of the instruction estimated part.

When the rear separation character can be detected within the displayrange and the front separation character may not be detected within thedisplay range, the control unit 20 applies the change in the searchrange to the searching of only the front character of the instructionestimated part.

Moreover, when the front separation character can be detected within thedisplay range and the rear separation character may not be detectedwithin the display range, the control unit 20 applies the change in thesearch range to the search for only the rear character of theinstruction estimated part.

Accordingly, when the selection unit 28 does not detect the frontseparation character within the beginning search ranges SE3 and SE5, theselection unit 28 determines whether the beginning search ranges SE3 andSE5 are changed in accordance with the previous setting details andperforms the same processing as that of the second selection methoddescribed above.

However, when the selection unit 28 changes the beginning search rangesSE3 and SE5, the selection unit 28 changes only the ends of thebeginning search ranges SE3 and SE5 and does not perform the processingof using the search ranges SE1 and SE2 again.

Moreover, when the selection unit 28 does not detect the rear separationcharacter within the finishing search ranges SE4 and SE6, the selectionunit 28 determines whether the search ranges are changed in accordancewith the previous setting details and performs the same processing asthat of the second selection method described above.

However, when the selection unit 28 changes the finishing search rangesSE4 and SE6, the selection unit 28 changes only the ends of thefinishing search ranges SE4 and SE6 and does not perform the processingof using the search ranges SE1 and SE2 again.

Thus, the selection unit 28 appropriately detects, as the frontcharacter of the instruction estimated part, the front separationcharacter, the front character of the display range, and the frontcharacter of one page from the text of the display range or one page.

Moreover, the selection unit 28 appropriately detects, as the rearcharacter of the instruction estimated part, the rear separationcharacter, the rear character of the display range, and the rearcharacter of one page from the text of the display range or one page.

Then, the selection unit 28 selects, as the instruction estimated part,for example, the phrase, the clause, or the like of the range from thedetected front character to the detected rear character from the text ofthe display range or one page.

Thus, even when the method of instructing the desired part of the textby the user tends to be varied, the selection unit 28 can reasonablyaccurately select the part estimated to be instructed by the user as theinstruction estimated part from the text of the display range or onepage.

When the selection unit 28 performs the selection processes in thismanner to select the instruction estimated part from the text of thedisplay range or the text of one page, the selection unit 28 extracts apage number from the region correspondence text data.

The selection unit 28 also extracts, from the region correspondence textdata, the instruction estimated part (that is, the plurality ofcharacters expressing the instruction estimated part) and the characterposition information (that is, regarding the plurality of charactersexpressing the instruction estimated part) regarding the instructionestimated part.

Moreover, the selection unit 28 stores the page number, the instructionestimated part, and the character position information and generatesinstruction estimated part data indicating the instruction estimatedpart. Then, the selection unit 28 transmits both the instructionestimated part data and the book attribute data to the acquisition unit29.

When the acquisition unit 29 receives the instruction estimated partdata and the book attribute data from the selection unit 28, theacquisition unit 29 transmits the instruction estimated part data to thenatural language processing block 30 and asks the natural languageprocessing block 30 to perform natural language processing on theinstruction estimated part data.

Moreover, the acquisition unit 29 temporarily maintains the bookattribute data until the acquisition unit 29 asks the natural languageprocessing block 30 to analyze the instruction estimated part data andobtains the analysis result.

As shown in FIG. 16, the natural language processing block 30 includes amorpheme analysis unit 30A, a syntax analysis unit 30B, and a dictionarystorage unit 30C. The dictionary storage unit 30C in advance storesmorpheme dictionary data generated by matching reading, word classes,and the like of the morphemes to a plurality of morphemes of variousword classes such as nouns, verbs, auxiliary words, and adverbs.

A morpheme refers to a minimum unit that has a meaning as a language.Examples of the morpheme include a morpheme that singly forms a word, amorpheme that forms a word in combination with another morpheme, and amorpheme that does not singly form a word and does not form a word incombination with another morpheme.

The dictionary storage unit 30C in advance stores semantic dictionarydata indicating a specific word of the word classes such as nouns andverbs and hierarchically indicating the meaning of this word in asuperordinate concept.

For example, when a specific word is a noun “ramen” (noodles) or “udon”(wheat noodles), the semantic dictionary data indicates two hierarchicalmeanings of the superordinate concept “cooking: kind of noodles” as themeaning of the word.

For example, when a specific word is a verb “eat”, the semanticdictionary data indicates two hierarchical meanings of the superordinateconcept “motion: meal” as the meaning of the word.

The morpheme analysis unit 30A of the natural language processing block30 acquires the instruction estimated part data from the acquisitionunit 29 and reads the morpheme dictionary data and the semanticdictionary data from the dictionary storage unit 30C in response to theacquisition.

Based on the morpheme dictionary data, the morpheme analysis unit 30Aanalyzes the instruction estimated part (that is, the character string)which is based on the instruction estimated part data. Then, themorpheme analysis unit 30A separates the instruction estimated part intoa plurality of morphemes and specifies the respective word classes ofthe plurality of morphemes.

Based on the plurality of morphemes, the word classes of the morphemes,and the semantic dictionary data, the morpheme analysis unit 30Adetermines a single or a plurality of morphemes that form a specificword with the word class such as a noun or a verb among the plurality ofmorphemes. Moreover, the morpheme analysis unit 30A specifies themeaning of the word formed by the determined single or plurality ofmorphemes.

The morpheme analysis unit 30A generates morpheme analysis result dataindicating the analysis result (the plurality of morphemes and wordclasses, the single or plurality of morphemes forming the determinedword among the plurality of morphemes, and the meaning of the wordformed by the single or plurality of morphemes) of the instructionestimated part. The morpheme analysis unit 30A transmits both themorpheme analysis result data and the instruction estimated part data tothe syntax analysis unit 30B.

When the syntax analysis unit 30B receives the morpheme analysis resultdata and the instruction estimated part data from the morpheme analysisunit 30A, the syntax analysis unit 30B analyzes the syntax of theinstruction estimated part, which is based on the instruction estimatedpart data, based on the morpheme analysis result data.

Then, the syntax analysis unit 30B specifies the grammatical role of themorpheme of the instruction estimated part and specifies this morpheme,modification of the morpheme, and the like in the instruction estimatedpart.

The syntax analysis unit 30B generates syntax analysis result dataindicating the analysis result (the grammatical role of the morphemes ofthe instruction estimated part and the modification or the like of themorpheme) of the instruction estimated part.

The syntax analysis unit 30B transmits the estimated part analysisresult data and the instruction estimated part data as an estimated partanalysis result data, which indicates the natural language processingresult of the instruction estimated part, together with the syntaxanalysis result data and the morpheme analysis result data to theacquisition unit 29.

When the acquisition unit 29 receives the estimated part analysis resultdata and the instruction estimated part data from the natural languageprocessing block 30, the acquisition unit 29 transmits the estimatedpart analysis result data and the instruction estimated part datatogether with the temporarily maintained book attribute data to thespecifying unit 33.

When the specifying unit 33 receives the estimated part analysis resultdata, the instruction estimated part data, and the book attribute datafrom the acquisition unit 29, the specifying unit 33 performs a processof specifying the desired part selected by the user in the instructionestimated part, which is based on the instruction estimated part data,based on the estimated part analysis result data.

As shown in FIG. 17, the specifying unit 33 specifies a desired partWA1, such as a phrase or clause, in the instruction estimated part EA1based on the morphemes, the modification of a word, or the like includedin the instruction estimated part EA1.

Then, the specifying unit 33 extracts a page number from the instructionestimated part data, when the specifying unit 33 specifies a part of theinstruction estimated part EA1 as the desired part WA1.

Moreover, the specifying unit 33 extracts, from the instructionestimated part data, the desired part WA1 (that is, the character codesof a plurality of characters expressing the desired part WA1) and thecharacter position information (regarding the plurality of charactersexpressing the desired part WA1) corresponding to the desired part WA1.

The specifying unit 33 stores the page number, the desired part WA1, andthe character position information and generates desired part dataindicating the desired part A1. Then, the specifying unit 33 transmitsboth the desired part data and the book attribute data to theregistration unit 34.

The specifying unit 33 extracts book identification information from thebook attribute data and also extracts the page number and characterposition information (hereinafter, also referred to as front characterposition information) regarding the position of the front character ofthe desired part WA1 from the instruction estimated part data.

Moreover, the specifying unit 33 extracts all of the informationindicating the analysis results of the morpheme analysis and the syntaxanalysis of the desired part WA1 from the estimated part analysis resultdata.

The specifying unit 33 stores the book identification information, thepage number, the front character position information, and informationindicating the analysis results of the morpheme analysis and the syntaxanalysis of the desired part WA1 and generates desired part analysisresult data indicating the analysis result of the desired part WA1.Then, the specifying unit 33 transmits the desired part analysis resultdata to the detection unit 35.

When the specifying unit 33 specifies the entire instruction estimatedpart EA1 as the desired part WA1, the specifying unit 33 transmits theinstruction estimated part data and the desired part data together withthe book attribute data without change to the registration unit 34.

At this time, the specifying unit 33 extracts the book identificationinformation from the book attribute data and extracts the page numberand the front character position information from the instructionestimated part data.

The specifying unit 33 adds the book identification information, thepage number, and the front character position information to theestimated part analysis result data, generates the desired part analysisresult data indicating the analysis result of the desired part WA1, andtransmits the generated desired part analysis result data to thedetection unit 35.

When the detection unit 35 receives the desired part analysis resultdata from the specifying unit 33, the detection unit 35 performs akeyword detection process of detecting important keywords from thedesired part WA1 in understanding the details of the desired part WA1based on the desired part analysis result data.

For example, the detection unit 35 maintains a list of word classes(hereinafter, also referred to as word class list) of the morphemes ofpredetermined word classes, such as auxiliary words or adverbs, whichhave been detected through learning of using various sentences inadvance and do not contribute to the understanding of the contents ofthe sentences.

For example, the detection unit 35 maintains a list (hereinafter, alsoreferred to as a meaning list) of the meanings of the words which havebeen detected through learning of using various sentences in advance andcontribute no understanding of the contents of the sentences.

Accordingly, the detection unit 35 excludes, from keyword candidates,the morphemes of the word classes registered in the word class listamong the plurality of morphemes included in the desired part WA1 sincethe morphemes registered in the word class list are not important to theunderstanding of the contents of the desired part WA1.

The detection unit 35 also excludes, from the keyword candidates, singleor a plurality of morphemes forming meaningful words registered in themeaning list among the plurality of words included in the desired partWA1, since the single or plurality of morphemes registered in themeaning list are not important to the understanding of the contents ofthe desired part WA1.

The detection unit 35 specifies the morphemes, which are not importantto the understanding of the contents of the desired part WA1 in thecontext of the desired part WA1, among the plurality of morphemes of thedesired part WA1 based on the grammatical role and the modification orthe like of the plurality of morphemes of the desired part WA1. Then,detection unit 35 excludes the specified morphemes from the keywordcandidates.

Thus, the detection unit 35 detects the words, such as nouns or verbs,forming the remaining single or plurality of morphemes among theplurality of morphemes of the desired part A1 without excluding theremaining morphemes, as keywords important to the understanding of thecontents of the desired part WA1.

When the detection unit 35 detects the keywords, the detection unit 35summarizes the detection result and gives a request of the number ofdetected keywords for each keyword (that is, respective differentkeywords).

That is, when the detected keyword is different from the detected otherkeyword, the detection unit 35 considers the number of detected keywordsto be one.

When the detected same keyword is two or more, the detection unit 35summarizes the keywords and considers the number of detected keywords tobe two or more.

The detection unit 35 appropriately weights the number of detectedkeywords for each keyword based on the grammatical role of the wordsformed by the keywords (that is, single or a plurality of morphemes)within the desired part WA1. For example, when the keyword is thesubject of a clause in the desired part WA1, the detection unit 35weights the number of detected keywords by one.

Thus, the detection unit 35 assigns the weighted number of detectedkeywords to the keyword as a score, which indicates how important akeyword is to the understanding of the contents of the desired part WA1,for each keyword.

When the detection unit 35 assigns the score to the keyword, thedetection unit 35 extracts the detected keyword (that is, the word (theplurality of characters expressing the word including single or aplurality of morphemes) detected as the keyword) from the desired partanalysis result data so as not to overlap.

The detection unit 35 extracts a character string (hereinafter, alsoreferred to as a meaning word) expressing the meaning of the keywordfrom the desired part analysis result data and also extracts the bookidentification information, the page number, and the front characterposition information from the desired part analysis result data.

The detection unit 35 stores the keyword, the meaning word, the score,the book identification information, the page number, and the frontcharacter position information for each keyword and generates keyworddetection data indicating the detection result of the keyword. Then, thedetection unit 35 transmits the keyword detection data to theregistration unit 34 and the tag generation unit 36.

When the tag generation unit 36 receives the keyword detection data fromthe detection unit 35, the tag generation unit 36 performs a taggeneration process of automatically generating a word (hereinafter, alsoreferred to as a tag) expressing the contents of the desired part WA1using the meaning word expressing the meaning of the keyword.

At this time, for example, the tag generation unit 36 extracts themeaning word for each keyword from the keyword detection data. Moreover,the tag generation unit 36 decomposes the meaning word hierarchicallyindicating the meaning of each keyword in the superordinate concept intowords expressing one meaning.

However, since the two meanings of the keyword are expressed in thesuperordinate concept, at least one meaning is the same as at least onemeaning of another keyword in some cases.

Therefore, when the tag generation unit 36 decomposes the meaning wordexpressing two meanings of a keyword into two words and obtains the twoor more same words, the same words are set to be one word so as not tooverlap with each other.

For example, the tag generation unit 36 maintains a list (hereinafter,also referred to as a word list) of words which have been detectedthrough a learning of using various sentences in advance, which do notexpress the contents of the sentence easily, and express a predeterminedmeaning.

Accordingly, the tag generation unit 36 excludes the word, which is thesame as the word registered in the word list among the words expressingthe individual meanings of the keywords, from tag candidates, since itis difficult to express the contents of the desired part WA1.

The tag generation unit 36 sets the remaining single or plurality ofwords, which are not excluded among the words expressing the individualmeanings of the keywords, as the tag expressing the contents of thedesired part WA1.

Thus, when the tag generation unit 36 generates the tag, the taggeneration unit 36 extracts the score assigned to the meaning keywordexpressed by the tag from the keyword detection data.

The tag generation unit 36 summarizes the scores assigned to the singleor plurality of keywords of the meaning expressed by the tag. Then, thetag generation unit 36 assigns the scores summarized for each tag to thetags as the scores indicating how accurately the tag expresses thecontents of the desired part WA1.

As for two words expressing two meanings of one keyword, the taggeneration unit 36 sets the score of the one keyword as the scores oftwo respective words.

When the tag generation unit 36 generates the tag and assigns the scoreto the tag, the tag generation unit 36 extracts the book identificationinformation, the page number, and the front character positioninformation from the keyword detection data.

The tag generation unit 36 stores the tag, the score, the bookidentification information, the page number, and the front characterposition information for each of the generated tags and generates taggeneration data indicating the generation result of the tag. Then, thetag generation unit 36 transmits the tag generation data to theregistration unit 34.

The storage unit 25 stores an electronic book with the selected desiredpart and a book registration database configured to register the desiredpart. In the storage unit 25, a data table used to register anelectronic book and a data table used to register the desired part areactually generated in the book registration database.

In the following description, the data table used to register anelectronic book is also referred to as a book registration table and thedata table used to register the desired part is also referred to as adesired part registration table.

The storage unit 25 further stores a keyword registration databaseconfigured to register the keywords detected from the desired part. Inthe storage unit 25, a data table used to register the keywords and adata table used to associate the keywords with the detected desiredparts are actually generated in the keyword registration database.

In the following description, the data table used to register thekeywords is also referred to as a keyword registration table and thedata table used to associate the keywords with the detected desiredparts is also referred to as a keyword association table.

The storage unit 25 further stores a tag registration databaseconfigured to register the tags generated for the desired parts. In thestorage unit 25, a data table used to register the tags and a data tableused to associate the tags with the detected desired parts, in which thecontents are expressed by the tags, are actually generated in the tagregistration database.

In the following description, the data table used to register the tagsis also referred to as a tag registration table and the data table usedto associate the tags with the desired parts is also referred to as atag association table.

As shown in FIG. 18, a book registration table DT1 in the bookregistration database includes, as information registration items, abook identification information registration item 37 used to registerthe book identification information and a book kind registration item 38used to register the kinds of electronic books.

The book registration table DT1 further includes, as informationregistration items, a title registration item 39 used to register thetitles of books and a publisher name registration item 40 used toregister the publisher names of the electronic books.

When the registration unit 34 receives the desired part data and thebook attribute data from the specifying unit 35, the registration unit34 extracts the book identification information from the book attributedata. Then, based on the book identification information, theregistration unit 34 determines whether the electronic book with theselected desired part has already been registered in the bookregistration table DT1 of the storage unit 25.

As a consequence, when the registration-unit 34 detects that theelectronic book with the selected desired part has not yet beenregistered in the book registration table DT1 of the storage unit 25,the registration unit 34 transmits the book attribute data as the bookregistration data to the storage unit 25.

Then, the registration unit 34 associates the book identificationinformation, the kinds of books, the titles of books, and the publishernames stored in the book registration data with each other and storesthe book identification information, the kinds of books, the titles ofbooks, and the publisher names in the information registration itemcorresponding to the book registration table DT1.

At this time, the registration unit 34 stores the book registration dataindicating the electronic book with the selected desired part in thebook registration table DT1 of the book registration database andregisters the electronic book with the selected desired part.

On the other hand, when the registration unit 34 detects that theelectronic book with the selected desired part has already beenregistered in the book registration table DT1 of the storage unit 25,the registration unit 34 does not register the electronic book in thebook registration table DT1.

Then, when registration unit 34 detects that the registration of theelectronic books is completed or the registration has already beencompleted, the registration unit 34 continues issuing identificationinformation (hereinafter, also referred to as desired partidentification information) used to individually identify the desiredpart indicated by the desired part data.

The registration unit 34 extracts the page number, the front characterposition information indicating the position of the front character ofthe desired part, and the desired part from the desired part data anddetects the number of characters of the desired part based on thecharacter position information stored in the desired part data.

The registration unit 34 further extracts the book identificationinformation from the book attribute data. Moreover, the registrationunit 34 stores the desired part identification information, the bookidentification information, the page number, the front characterposition information, the number of characters, and the desired part(that is, the plurality of characters expressing the desired part) andgenerates the desired part registration data for the desired partregistration. Then, the registration unit 34 transmits the desired partregistration data to the storage unit 25.

As shown in FIG. 19, a desired part registration table DT2 in the bookregistration database includes, as information registration items, adesired part identification information registration item 41 used toregister the desired part identification information and a bookidentification information registration item 42 used to register thebook identification information.

The desired part registration table DT2 includes, as informationregistration items, a page number registration item 43 used to registerthe page number of a page where the desired part is present and a linenumber registration item 44 used to register the line number of the linewhere the front character of the desired part is located.

The desired part registration table DT2 further includes, as informationregistration items, a column number registration item 45 used toregister the column number of the column where the front character ofthe desired part is located and a character number registration item 46used to register the number of characters of the desired part.

The desired part registration table DT2 further includes, as aninformation registration item, a desired part registration item 47 usedto register the desired part itself as a character string.

The registration unit 34 associates the desired part identificationinformation, the book identification information, the page number, therow number, the column number, the number of characters, and the desiredpart stored in the desired part registration data with each other. Theregistration unit 34 stores the desired part identification information,the book identification information, the page number, the row number,the column number, the number of characters, and the desired part in theinformation registration item corresponding to the desired partregistration table DT2.

The registration unit 34 stores the desired part registration dataindicating the selected desired part in the desired part registrationtable DT2 of the book registration database and registers the desiredpart.

When the registration unit 34 receives the keyword detection data fromthe detection unit 35, the registration unit 34 issues identificationinformation (hereinafter, also referred to as keyword identificationinformation) used to individually identify the keywords stored in thekeyword detection data.

The registration unit 34 extracts a keyword (that is, a plurality ofcharacters expressing the keyword), the morpheme attribute informationof the keyword, and the score of the keyword from the keyword detectiondata.

The registration unit 34 stores the keyword identification information,the keyword, the morpheme attribute information, and the score andgenerates the keyword registration data for keyword registration. Then,the registration unit 34 transmits the keyword registration data to thestorage unit 25.

As shown in FIG. 20, a keyword registration table DT3 in the keywordregistration database includes, as an information registration item, akeyword identification information registration item 48 used to registerthe keyword identification information.

The keyword registration table DT3 further includes, as informationregistration items, a keyword registration item 49 used to register thekeyword itself as the character string and a word class registrationitem 50 used to register the word class of the keyword.

The keyword registration table DT3 further includes, as informationregistration items, a meaning registration item 51 used to register themeaning (in effect, a meaning word expressing the meaning) of thekeyword and a keyword score registration item 52 used to register thescore of the keyword.

Then, the registration unit 34 associates the keyword identificationinformation, the keyword, the word class, the meaning word, and thescore stored in the keyword registration data with each other for eachkeyword. The registration unit 34 stores the keyword identificationinformation, the keyword, the word class, the meaning word, and thescore in the information registration items corresponding to the keywordregistration table DT3.

At this time, the registration unit 34 stores the keyword registrationdata indicating the keyword detected from the desired part in thekeyword registration table DT3 of the keyword registration database andregisters the keyword.

When the registration unit 34 receives the tag generation data from thetag generation unit 36, the registration unit 34 issues identificationinformation (hereinafter, also referred to as tag identificationinformation) used to individually identify the tags stored in the taggeneration data. The registration unit 34 extracts the tag (that is, theplurality of characters expressing the tag) from the tag generationdata.

The registration unit 34 stores the tag identification information, thetag, and generation kind information indicating that the tag isautomatically generated by the tag generation unit 36 and generates thetag registration data for tag registration. Then, the registration unit34 transmits the tag registration data to the storage unit 25.

As shown in FIG. 21, a tag registration table DT4 in the tagregistration database includes, as an information registration item, atag identification information registration item 53 used to register thetag identification information.

The tag registration table DT4 further includes, as informationregistration items, a generation kind registration item 54 used toregister the generation kind information and a tag registration item 55used to register the tag as a character string.

The registration unit 34 associates the tag identification information,the generation kind information, and the tag stored in the tagregistration data with each other for each tag and stores the tagidentification information, the generation kind information, and the tagin the information registration item corresponding to the tagregistration table DT4.

At this time, the registration unit 34 stores the tag registration dataindicating the tag automatically generated for addition to the desiredpart in the tag registration table DT4 of the tag registration databaseand registers the tag.

The tags added to the desired part include not only the tagsautomatically generated by the tag generation unit 36 but also tags,such as “study”, “small material”, “memo”, and “presentation material”,selected arbitrarily by the user and added to the desired part.

Accordingly, the control unit 20 generates the tag generation data, whenthe desired part is selected by the user or the electronic book imagewith the selected desired part is displayed again and when the userexecutes a predetermined operation to select the desired part and singleor a plurality of tags added to the desired part. The control unit 20transmits the tag generation data to the registration unit 34.

That is, the control unit 20 extracts the book identificationinformation, the page number, and the front character positioninformation indicating the position of the front character of thedesired part from the book attribute data or the text data of theelectronic book with the selected desired part to which the tags areadded.

The control unit 20 automatically assigns the score indicating apredetermined value selected in advance to the tag. Then, the controlunit 20 generates the tag generation data, which stores the tag (thatis, single or a plurality of words expressing the tag), the score of thetag, the book identification information, the page number, the frontcharacter position information, and transmits the tag generation data tothe registration unit 34.

When the registration unit 34 receives the tag generation data from thecontrol unit 20, the registration unit 34 issues the tag identificationinformation used to individually identify the tags stored in the taggeneration data, as described above. Then, the registration unit 34extracts the tags from the tag generation data.

The registration unit 34 generates the tag registration data, whichstores the tag identification information, the tags, and the generationkind information indicating that the tag selected by the user is set tobe added to the desired part. Then, the registration unit 34 transmitsthe tag registration data to the storage unit 25.

The registration unit 34 associates the tag identification information,the generation kind information, and the tag stored in the tagregistration data with each other for each tag. The registration unit 34stores the tag identification information, the generation kindinformation, and the tag in the information registration itemcorresponding to the tag registration table DT4.

The registration unit 34 stores the tag registration data indicating thetag selected for the addition to the desired part by the user in the tagregistration table DT4 of the tag registration database and registersthe tag.

When the registration unit 34 registers the keywords in the keywordregistration table DT3, the registration unit 34 extracts the bookidentification information, the page number, and the front characterposition information from the keyword detection data.

The registration unit 34 stores the book identification information, thepage number, and the front character position information together withthe keyword identification information of the registered keywords andgenerates keyword association request data giving a request forassociating the keywords with the desired part. Then, the registrationunit 34 transmits the keyword association request data to theassociation unit 60.

When the association unit 60 receives the keyword association requestdata from the registration unit 34, the association unit 60 extracts thebook identification information, the page number, and the frontcharacter position information from the keyword association requestdata.

Based on the book identification information, the page number, and thefront character position information, the association unit 60 retrievesthe desired part identification information of the desired partcorresponding to the keyword registered in the registration unit 34 fromthe desired part registration table DT2 of the storage unit 25.

The association unit 60 extracts the keyword identification informationfrom the keyword association request data and generates keywordassociation data for the keyword association in which the keywordidentification information is stored together with the retrieved desiredpart identification information. Then, the association unit 60 transmitsthe keyword association data to the storage unit 25.

As shown in FIG. 22, a keyword association table DT5 in the keywordregistration database includes, as an information registration item, adesired part identification information registration item 61 used toregister the desired part identification information.

The keyword association table DT5 includes, as in informationregistration item, a keyword identification information registrationitem 62 used to register the keyword identification information.

Accordingly, the association unit 60 associates the desired partidentification information and the keyword identification informationstored in the keyword association data with each other for each keywordand stores the desired part identification information and the keywordidentification information in the information registration itemcorresponding to the keyword association table DT5.

The association unit 60 associates the desired part with the keywordsdetected from the desired part using the keyword association table DT5of the keyword registration database.

When the registration unit 34 registers the tags in the tag registrationtable DT4, the registration unit 34 extracts the book identificationinformation, the page number, and the front character positioninformation from the tag generation data. Then, the registration unit 34extracts the score for each tag from the tag generation data.

The registration unit 34 stores the scores of each book identificationinformation, each page number, each front character positioninformation, and each tag extracted from the tag generation datatogether with the tag identification information for each tag issued atthis time and generates tag association request data used to make arequest for associating the tags with the desired part. Then, theregistration unit 34 transmits the tag association request data to theassociation unit 60.

When the association unit 60 receives the tag association request datafrom the registration unit 34, the association unit 60 extracts the bookidentification information, the page number, and the front characterposition information from the tag association request data.

Based on the book identification information, the page number, and thefront character position information, the association unit 60 retrievesthe desired part identification information of the desired partcorresponding to the tags registered in the registration unit 34 at thistime from the desired part registration table DT2 of the storage unit25.

The association unit 60 extracts the tag identification information andthe scores from the tag association request data and generates tagassociation data for tag association in which the tag identificationinformation and the scores are stored together with the retrieveddesired part identification information. Then, the association unit 60transmits the tag association data to the storage unit 25.

As shown in FIG. 23, a tag association table DT6 in the tag registrationdatabase includes, as information registration items, a desired partidentification information registration item 63 used to register thedesired part identification information and a tag identificationinformation registration item 64 used to register the tag identificationinformation.

The tag association table DT6 includes, as an information registrationitem, a tag score registration item 65 used to register the scores ofthe tags.

The association unit 60 associates the desired part identificationinformation, the tag identification information, and the scores storedin the tag association data with each other for each tag and stores thedesired part identification information, the tag identificationinformation, and the scores in the information registration itemcorresponding to the tag association table DT6.

The association unit 60 associates the desired part with the tags (thatis, the tags automatically generated and the tags selected by the user)added to the desired part using the tag association table DT6 of the tagregistration database.

For example, when the association unit 60 completely associates thedesired part and the tags, the association unit 60 stores the desiredpart identification information used for the association and generatesdesired part retrieval request data used to give a request forretrieving the desired part. Then, the association unit 60 transmits thedesired part retrieval request data to the retrieval unit 66.

When the retrieval unit 66 receives the desired part retrieval requestdata from the association unit 60, the retrieval unit 66 extracts thedesired part identification information from the desired part retrievalrequest data. Moreover, the retrieval unit 66 retrieves and reads, fromthe Storage unit 25, the row number, the column number, and the numberof characters associated with the desired part identificationinformation in the book registration table DT1.

Here, the row number, the column number, and the number of charactersassociated with the desired part identification information areinformation indicating the position of the desired part identified bythe desired part identification information in the text.

The retrieval unit 66 stores the desired part position information (thatis, the row number, the column number, the number of characters)indicating the position of the desired part in the text together withthe desired part identification information and generates desired partnotification data used to give a notification of the desired part. Then,retrieval unit 66 transmits the desired part notification data to thecontrol unit 20.

When the control unit 20 received the desired part notification datafrom the retrieval unit 66, the control unit 20 extracts the desiredpart position information and the desired part identificationinformation from the desired part notification data.

The control unit 20 stores the desired part position information and thedesired part identification information, generates emphasis displaycontrol data used to control the desired part so as to be emphasized,and transmits the generated emphasis display control data to the displaycontrol unit 26.

When the display control unit 26 receives the emphasis display controldata from the control unit 20, the display control unit 26 processes theelectronic book image data generated for display based on the emphasisdisplay control data and transmits the processed electronic book imagedata to the display, unit 21.

Thus, as shown in FIG. 24, the display control unit 26 displays thedesired part designated based on the emphasis display control data inthe emphasis manner so as to show the desired part to the user in theelectronic book image 27 being displayed on the display unit 21.

Thus, when the user selects the desired part on the electronic bookimage 27, the control unit 20 controls each circuit unit at each time toperform the series of processes described above.

Thus, the control unit 20 specifies the selected desired part andregisters various kinds of information regarding the desired part in thevarious databases in the storage unit 25. In addition, the control unit20 can displays the desired part in the electronic book image 27 in theemphasis manner.

When the display control unit 26 displays the desired part in theemphasis manner in the electronic book image 27 displayed on the displayunit 21, the display control unit 26 terminates the display of theelectronic book image 27 and maintains the emphasis display until theelectronic book image being displayed on the display unit 21 is newlyswitched.

As shown in FIG. 25, while one electronic book image 27 is displayed onthe display unit 21, whenever the sequentially desired parts areselected on the electronic book image 27, the display control unit 26newly displays the additionally selected desired part without a changein the emphasis display until that point.

Thus, when the user selects the desired parts, the control unit 20 candisplay the desired parts in the emphasis manner in the electronic bookimage 27 with the same sense as a sense of marking the desired partsusing a marker on a page of a book made of paper during the display ofthe electronic book image 27 on the display unit 21.

The control unit 20 extracts the book identification information fromthe book attribute data, when the electronic book image 27 beingdisplayed on the display unit 21 is newly switched or a newly selectedelectronic book is displayed.

Moreover, the control unit 20 also extracts the page number from theone-page text data being displayed at this time. Then, the control unit20 stores the book identification information and the page number,generates the desired part retrieval request data used to give a requestfor retrieving the desired part, and the transmits the generated desiredpart retrieval request data to the retrieval unit 66.

At this time, when the retrieval unit 66 receives the desired partretrieval request data from the control unit 20, the retrieval unit 66extracts the desired part identification information and the page numberfrom the desired part retrieval data.

The retrieval unit 66 searches for the desired part position informationcorresponding to the desired part identification information and thepage number in the book registration table DT1 of the storage unit 25based on the desired part identification information and the pagenumber.

As a consequence, when the desired part position informationcorresponding to the desired part identification information and thepage number is not registered in the book registration table DT1 of thestorage unit 25, the retrieval unit 66 notifies the control unit 20 thefact that the desired part position information is not registered.

At this time, the control unit 20 detects that no desired part isselected in the text of the electronic book image in response to thenotification from the retrieval unit 66. In this case, the control unit20 does not control the display control unit 26 so as to display thedesired part in the emphasis manner in response to the detection result.

On the other hand, when the retrieval unit 66 retrieves the desired partposition information associated with the desired part identificationinformation and the page number in the book registration table DT1 ofthe storage unit 25, the retrieval unit 66 reads the desired partposition information from the storage unit 25.

The retrieval unit 66 stores both the desired part position informationand the desired part identification information, generates the desiredpart notification data used to give a notification of the desired part,and transmits the generated desired part notification data to thecontrol unit 20.

When the control unit 20 receives the desired part notification datafrom the retrieval unit 66, as described above, the control unit 20generates the emphasis display control data based on the desired partnotification data and transmits the emphasis display control data to thedisplay control unit 26.

Then, the display control unit 26 processes the electronic book imagedata based on the emphasis display control data transmitted from thecontrol unit 20, transmits the processed electronic book image data tothe display unit 21, and displays single or a plurality of desired partsin the emphasis manner in the electronic book image 27 displayed on thedisplay unit 21.

Thus, when the control unit 20 newly switches the electronic book image27 displayed on the display unit 21 and newly displays an electronicbook and when the desired part has already been selected in theelectronic book image 27 newly displayed on the display unit 21, thecontrol unit 20 can display the desired part in the emphasis manner.

Since the control unit 20 prepares for plural kinds of method ofemphasizing and displaying the desired part, the user is permitted toarbitrarily select and set the kinds of method of emphasizing anddisplaying the desired part.

Thus, when the display unit 21 is capable of realizing color display, asshown in FIGS. 24 and 25, the control unit 20 can superimpose arbitrarycolors and shapes on the desired part to display the desired part in theemphasis manner.

When the display unit 21 is capable of realizing color display, thecontrol unit 20 can underline the desired part with the arbitrary kindsof line (straight line, wavy line, and the like) to display the desiredpart in the emphasis manner.

When the display unit 21 is capable of realizing color display, thecontrol unit 20 can surround the desired part with a frame of anarbitrary color and an arbitrary shape (formed by a straight line or acurved line) to display the desired part in the emphasis manner.

When the display unit 21 is capable of realizing color display, thecontrol unit 20 can display the characters of the desired part with anarbitrary color different from the color of the characters of anotherpart to display the desired part in the emphasis manner.

When the display unit 21 is capable of realizing color display, thecontrol unit 20 can mark the upper or lower of the individual charactersand the sides of the front and rear characters in the desired part withan arbitrary color and an arbitrary shape (such as a circle, a star, anda rectangle) to display the desired part in the emphasis manner.

When the display unit 21 is capable of realizing color display, thecontrol unit 20 can periodically vary at least one of the color, font,size, style, and the like of the character of the desired part todisplay the desired part in the emphasis manner.

When the display unit 21 is capable of realizing monochromic display,the control unit 20 can underline the desired part with the arbitrarykinds of line (straight line, wavy line, and the like) to display thedesired part in the emphasis manner.

When the display unit 21 is capable of realizing monochromic display,the control unit 20 can surround the desired part with a frame of anarbitrary color and an arbitrary shape (formed by a straight line or acurved line) to display the desired part in the emphasis manner.

When the display unit 21 is capable of realizing monochromic display,the control unit 20 can mark the upper or lower of the individualcharacters and the sides of the front and rear characters in the desiredpart with an arbitrary color and an arbitrary shape (such as a circle, astar, and a rectangle) to display the desired part in the emphasismanner.

When the display unit 21 is capable of realizing monochromic display,the control unit 20 can periodically vary at least one of the color,font, size, style, and the like of the character of the desired part todisplay the desired part in the emphasis manner.

When the display unit 21 is capable of realizing color display andmonochromic display, the control unit 20 can allow at least one of thefont, size, style, and the like of the character of the desired part todiffer from that of another character to display the desired part in theemphasis manner.

When the association unit 60 completely associates the keywords and thedesired part and then completely associates the keywords, the generatedtags, and the desired part with each other, the association unit 60generates association information retrieval request data used to give arequest for retrieving information associated with the desired part.

At this time, the association unit 60 stores the keyword identificationinformation and the desired part identification information used toassociate the keywords and the desired part with each other andgenerates the association information retrieval request data. Then, theassociation unit 60 transmits the association information retrievalrequest data to the retrieval unit 66.

When the retrieval unit 66 receives the association informationretrieval, request data from the association unit 60, the retrieval unit66 extracts the keyword

identification information from the association information retrievalrequest data. Moreover, the retrieval unit 66 retrieves and reads thekeywords identified with the keyword identification information in thekeyword registration table DT3 from the storage unit 25.

The retrieval unit 66 stores the keywords as retrieval keys and alsostores the upper limit designation information used to designate thepreset upper limit of a retrieval number. The retrieval unit 66generates retrieval request data used to ask a retrieval apparatus (notshown) on the network 13 to retrieve association information regardingthe desired part.

The retrieval unit 66 transmits the retrieval request data to thetransmission unit 23. Then, the transmission unit 23 transmits theretrieval request data transmitted from the retrieval unit 66 to theretrieval apparatus via the network 13.

At this time, the retrieval apparatus receives the retrieval requestdata transmitted from the information display terminal 11 and extractsthe keywords from the received retrieval request data. Then, theretrieval apparatus retrieves the association information (having a textincluding retrieval keys) associated with the desired part within thedesignated upper limit of the retrieval number from various kinds ofinformation read from a home page or the like publicized on the network13, by using the keywords as the retrieval keys.

The association information retrieved by the retrieval apparatus isinformation that is generally publicized on the network 13, as describedabove. In the following description, the association informationretrieved by the retrieval apparatus is also referred to as openassociation information.

The retrieval apparatus generates retrieval result data stored bymatching the title (hereinafter, also referred to as an associationinformation title) of the open association information with a networkaddress used to access the open association information for each titleof the retrieved open association information. The retrieval apparatusreplies the retrieval result data to the information display terminal 11via the network 13.

Then, the reception unit 24 receives the retrieval result data receivedfrom the retrieval apparatus and transmits the received retrieval resultdata to the retrieval unit 66.

When the retrieval unit 66 receives the retrieval result data from thereception unit 24, the retrieval unit 66 extracts the associationinformation title and the network address of each of the openassociation information retrieved by the retrieval apparatus from theretrieval result data.

The retrieval unit 66 extracts the desired part identificationinformation from the association information retrieval request data. Theretrieval unit 66 retrieves and reads the tag identification informationassociated with the desired part identification information in the tagassociation table DT6 from the storage unit 25.

The retrieval unit 66 stores the association information title and thenetwork address for each of the open association information retrievedby the retrieval apparatus together with the retrieved tagidentification information and generates association informationregistration data used to register the open association information.Then, the retrieval unit 66 transmits the association informationregistration data to the association unit 60.

Here, association information registration database is constructed inadvance in the storage unit 25. Moreover, the association informationregistration database includes a data table (hereinafter, also referredto as an information association table) used to associate the tags ofthe desired part with the association information of the desired part.

The association unit 60 transmits the association informationregistration data transmitted from the retrieval unit 66 to the storageunit 25. The association unit 60 associates the association informationtitle of each of the open association information stored in theassociation information registration data, the network address, and thetag identification information and stores the result in the informationassociation table in the storage unit 25.

Thus, the association unit 60 registers the open association informationassociated with the desired part in association with the tags of thedesired part by using the information association table of theassociation information registration database.

When the retrieval unit 66 generates the association informationregistration data indicating the open association information, asdescribed above, and transmits the association information registrationdata to the association unit 60, the retrieval unit 66 continuesretrieving the electronic book as the association information associatedwith the desired part among the electronic books which have already beenstored in the storage unit 25.

At this time, based on the keywords read from the storage unit 25, theretrieval unit 66 detects whether the same keywords as these keywordsare registered in the keyword registration table DT3 of the storage unit25.

The keywords read from the storage unit 25 by the retrieval unit 66 aredetected from the desired part by the detection unit 35 and are newlyregistered in the keyword registration table DT3 by the registrationunit 34. In the following description, keywords read from the storageunit 25 by the retrieval unit 66 are also referred to as newregistration keyword.

As a consequence, when the retrieval unit 66 retrieves the same keywordsas the new registration keywords among the keywords having alreadyregistered in the keyword registration table DT3, the retrieval unit 66reads the keyword identification information of the keywords retrievedfrom the storage unit 25.

In the following description, the keywords which are retrieved as thenew registration keyword among the keywords having already registeredand are same as the new registration keywords are also referred toidentical keywords. In the following description, keyword identificationinformation of the identical keyword is also referred to as registeredkeyword identification information.

The retrieval unit 66 retrieves and reads, from the storage unit 25, thedesired part identification information (hereinafter, also referred toas registered desired part identification information) associated withthe registered keyword identification information in the keywordassociation table DT5.

The retrieval unit 66 retrieves and reads, from the storage unit 25, thebook identification information (hereinafter, also referred to as aretrieval book identification information) associated with theregistered desired part identification information in the desired partregistration table DT2.

At this time, the retrieval unit 66 retrieves and reads, from thestorage unit 25, the book identification information associated with thedesired part identification information in the desired part registrationtable DT2 based on the desired part identification information extractedfrom the association information retrieval request data.

The desired part identification information extracted from theassociation information retrieval request data by the retrieval unit 66is information that is newly registered in the desired part registrationtable DT2 by the registration unit 34. In the following description, thedesired part identification information extracted from the associationinformation retrieval request data by the retrieval unit 66 is alsoreferred to as new registration desired part identification information.

The book identification information associated with the new registrationdesired part identification information is the book identificationinformation of the electronic book (hereinafter, also referred to as anelectronic book being displayed) with the selected desired partidentified with the new registration desired part identificationinformation. In the following description, the book identificationinformation associated with the new registration desired partidentification information is also referred to as book identificationinformation being displayed.

The retrieval unit 66 compares the retrieval book identificationinformation and the book identification information being displayed,which have been read from the storage unit 25, to each other. Based onthe comparison result, the retrieval unit 66 determines whether anotherelectronic book, which is different from the electronic book beingdisplayed and includes the same keywords as the new registrationkeywords in the text, is retrieved as the retrieval book identificationinformation.

That is, the retrieval unit 66 determines whether there is retrieved theelectronic book associated with the desired part in which the newregistration keywords are detected since the electronic book isdifferent from the electronic book being displayed, but includes theidentical keywords which are the same as the new registration keywordsin the text.

When the retrieval unit 66 retrieves the association electronic book,the retrieval unit 66 reads, from the storage unit 25, the page numberand the desired part position information associated with the registereddesired part identification information used to retrieve the retrievalbook identification information of the association electronic book inthe desired part registration table DT2.

Based on the retrieval book identification information of theassociation electronic book, the retrieval unit 66 also reads the booktitle associated with the retrieval book identification information inthe book registration table DT1 from the storage unit 25.

Based on the registered desired part identification information used toretrieve the retrieval book identification information of theassociation electronic book, the retrieval unit 66 retrieves and readsthe tag identification information associated with the registereddesired part identification information in the tag association table DT6from the storage unit 25.

The retrieval unit 66 stores the book title, tag identificationinformation, the retrieval book identification information, the pagenumber, and the desired part position information read from the storageunit 25, generates the association information registration dataindicating the association electronic book, and transmits the generatedassociation information registration data to the association unit 60.

Thus, the retrieval unit 66 retrieves the association electronic bookassociated with the desired part in which the new registration keywordsof the electronic book being displayed are detected among the electronicbooks stored in the storage unit 25.

At this time, the association unit 60 transmits the associationinformation registration data transmitted from the retrieval unit 66 tothe storage unit 25. The association unit 60 associates the tagidentification information with the book title, the retrieval bookidentification information, the page number, and the desired partposition information of each association electronic book stored in theassociation information registration data and stores the result in theinformation association table in the storage unit 25.

The association unit 60 registers the association electronic bookassociated with the selected desired part in association with the tag ofthe desired part by using the information association table of theassociation information registration database.

When the user selects both the desired part and an arbitrary tag addedto the desired part, the control unit 20 can permit an input of anarbitrary comment (hereinafter, also referred to as an associationcomment) as the association information associated with the desiredpart.

Therefore, when the user selects both the desired part and an arbitrarytag added to the desired part and executes a predetermined operation toinput the association comment, the control unit 20 generates the taggeneration data that further stores the association comment. Then, thecontrol unit 20 transmits the tag generation data to the associationunit 60.

At this time, the registration unit 34 registers the tag selected by theuser so as to be added to the desired part in the tag registration tableDT4 by generating the tag registration data based on the tag generationdata and transmitting the tag registration data to the storage unit 25,as described above.

When the user inputs the association comment, the registration unit 34extracts the book identification information, the page number, the frontcharacter position information, the score of each tag, and theassociation comment from the tag generation data.

Moreover, the registration unit 34 generates tag association requestdata in which the book identification information, the page number, thefront character position information, the score of each tag, and theassociation comment extracted from the tag generation data are storedtogether with the tag identification information of each tag issued atthis time. Then, the registration unit 34 transmits the tag associationrequest data to the association unit 60.

When the association unit 60 receives the tag association request datafrom the registration unit 34, as described above, the association unit60 associates the desired part with the tag added to the desired partusing the tag association table DT6 based on the tag association requestdata.

At this time, the association unit 60 extracts the association commentof each tag from the tag association request data. Moreover, theassociation unit 60 stores both the association comment of each tag andthe tag identification information extracted from the tag associationrequest data at this time and generates the association informationregistration data indicating the association comment.

Then, the association unit 60 transmits the association informationregistration data to the storage unit 25. Thus, the association unit 60associates the association comment of each tag stored in the associationinformation registration data with the tag identification informationand stores the result in the information association table in thestorage unit 25.

Thus, the association unit 60 registers the association commentassociated with the desired part selected at this time in associationwith the tag of the desired part by using the information associationtable of the association information registration database.

When the association information associated with the desired part can beassociated with the tag of the desired part, the control unit 20 candisplay the association information in response to, for example, a tapoperation on the electronic book image being displayed on the displayunit 21.

In effect, the control unit 20 instructs the display control unit 26 todisplay the desired part in the emphasis manner based on the desiredpart notification data described above. Accordingly, the display controlunit 26 displays the desired part in the emphasis manner in theelectronic book image being displayed on the display unit 21 in responseto the instruction to display the desired part in the emphasis manner.

In this case, the display control unit 26 generates desired part displayregion information indicating the display region of the desired partusing the coordinates of the pixel position of the display surface ofthe display unit 21, while the display control unit 26 displays thedesired part in the emphasis manner in the electronic book image 27being displayed on the display unit 21.

The display control unit 26 transmits both the desired part displayregion information of the desired part and the desired partidentification information of the desired part to the control unit 20.

While the desired part is displayed in the emphasis manner, the controlunit 20 matches the desired part display region information and thedesired part identification information of the desired part transmittedfrom the display control unit 26 with each other and maintains thedesired part display region information and the desired partidentification information.

When the desired part is displayed in the emphasis manner in theelectronic book image 27 being displayed on the display unit 21 and theuser taps the surface of the touch panel, the control unit 20 comparesthe touch position of the tap operation to the display region of thedesired part indicated by the desired part display region information.

As a consequence, the control unit 20 determines the desired part isinstructed by the tap operation, when the control unit 20 detects thatthe tap operation within the display region of the desired part.

At this time, the control unit 20 detects the desired partidentification information matched with the desired part display regioninformation based on the desired part display region informationindicating the tapped display region.

The control unit 20 stores the desired part identification information(that is, the desired part identification information of the instructeddesired part) detected in response to the tap operation and generatestag request data used to give a request of the tag of the desired part.Then, the control unit 20 transmits the tag request data to theretrieval unit 66.

When the retrieval unit 66 receives the tag request data from thecontrol unit 20, the retrieval unit 66 extracts the desired partidentification information from the tag request data. The retrieval unit66 retrieves and reads, from the storage unit 25, the tag identificationinformation and the score associated with the desired partidentification information in the tag association table DT6.

Moreover, the retrieval unit 66 reads, from the storage unit 25, the tagassociated with the tag identification information in the tagregistration table DT4 based on the tag identification information readfrom the storage unit 25.

The retrieval unit 66 generates tag supply data, which stores the tag,the score, and the tag identification information of each tag and thedesired part identification information extracted from the tag requestdata, and returns the generated tag supply data to the control unit 20.

When the control unit 20 receives the tag supply data from the retrievalunit 66, the control unit 20 extracts the desired part identificationinformation and the tag, the score, the tag identification informationof each tag from the tag supply data.

Based on the desired part identification information, the control unit20 specifies the desired part display region information indicating thedisplay region of the desired part (that is, the desired part instructedat this time) identified with the desired part identificationinformation.

The control unit 20 stores the tag and the tag identificationinformation added to the instructed desired part together with thedesired part display region information indicating the display region ofthe desired part and generates tag display control data used to matchthe tag with the instructed desired part and display the tag and theinstructed desired part.

Here, when only one tag is added to the instructed desired part, thecontrol unit 20 generates tag display control data which stores the onetag together with the tag identification information and the desiredpart display region information.

Moreover, when a plurality of tags are added to the desired part, thecontrol unit 20 permits the user to arbitrarily select a method ofdisplaying the tags, such as a method of displaying all of the tags, amethod of displaying the tags with a score equal to or greater than apredetermined score selected in advance, and a method of displaying onetag with the highest score.

Therefore, when the plurality of tags is added to the instructed desiredpart, the control unit 20 selects the tags to be displayed in responseto the previous setting. Then, the control unit 20 generates the tagdisplay control data which stores the selected tags together with thetag identification information and the desired part display regioninformation.

Thus, when the control unit 20 generates the tag display control data,the control unit 20 transmits the generated tag display control data tothe display control unit 26.

When the display control unit 26 receives the tag display control datafrom the control unit 20, the display control unit 26 processes theelectronic book image data generated for display so as to furtherdisplay the tags based on the tag display control data and transmits theprocessed electronic book image data to the display unit 21.

As shown in FIG. 26, the display control unit 26 displays a tag TG addedto the desired part instructed by the user on the electronic book image27 being displayed on the display unit 21 by matching the tag TG withthe desired part.

Thus, the control unit 20 can exhibit the tag TG expressing the contentsof the desired part to the user together with the desired part (that is,the emphasized desired part) via the electronic book image 27 beingdisplayed on the display unit 21.

While the display control unit 26 displays the tag TG on the electronicbook image 27 being on the display unit 21, the display control unit 26generates tag display region information indicating the display regionof the tag TG being displayed with the coordinates of the pixel positionon the display surface of the display unit 21. Then, the display controlunit 26 transmits both the tag display region information of the tag TGand the tag identification information of the tag TG to the control unit20.

During the display of the tag TG, the control unit 20 maintains the tagdisplay region information and the tag identification information of thetag TG transmitted from the display control unit 26 by matching the tagdisplay region information with the tag identification information.

Therefore, when the user taps the surface of the touch panel during thedisplay of the tag TG on the electronic book image 27 being displayed onthe display unit 21, the control unit 20 compares the touch position ofthe tap operation to the display region of the tag TG indicated by thetag display region information.

As a consequence, when the control unit 20 detects that user taps thedisplay region of the tag TG, the control unit 20 determines that thetag TG is instructed by the tap operation.

At this time, the control unit 20 detects the tag identificationinformation matched with the tag display region information based on thetag display region information indicating the tapped display region.

The control unit 20 stores the tag identification information (that is,the tag identification information of the instructed tag TG) detected inresponse to the tap operation and generates association informationrequest data giving a request of the association information. Then, thecontrol unit 20 transmits the association information request data tothe retrieval unit 66.

When the retrieval unit 66 receives the association information requestdata from the control unit 20, the retrieval unit 66 extracts the tagidentification information from the association information requestdata. At this time, when the open association information can beassociated with the instructed tag TG, the retrieval unit 66 retrievesand reads, from the storage unit 25, the association information titleand the network address of each open association information associatedwith the tag identification information in the information associationtable.

When the association electronic book can be associated with theinstructed tag TG, the retrieval unit 66 also retrieves and reads, fromthe storage unit 25, the book title, the book identificationinformation, the page number, the desired part position information ofeach association electronic book associated with the tag identificationinformation in the information association table.

When the association comment can be associated with the instructed tagTG, the retrieval unit 66 also retrieves and reads, from the storageunit 25, the association comment associated with the tag identificationinformation in the information association table.

Moreover, the retrieval unit 66 generates association information supplydata, which stores the tag identification information used in theretrieving, the association information title and the network address ofeach of the open association information, the book title of eachassociation electronic book, the book identification information, thepage number, the desired part position information, and the associationcomment. Then, the retrieval unit 66 returns the association informationsupply data to the control unit 20.

At this time, the control unit 20 extracts, from the associationinformation supply data, the tag identification information, theassociation information title and the network address of each of theopen association information, the book title of each associationelectronic book, the book identification information, the page number,the desired part position information, and the association comment.

Moreover, based on the tag identification information, the control unit20 specifies the tag display region information indicating the displayregion of the tag TG (that is, the tag TG instructed at this time)identified with the tag identification information.

The control unit 20 stores the association information title or the booktitle, the association comment, and the specified tag display regioninformation and generates association information display control dataused to display the association information title or the book title andthe association comment by matching the association information title orthe book title and the association comment with the tag TG. Then, thecontrol unit 20 transmits the association information display controldata to the display control unit 26.

When the display control unit 26 receives the association informationdisplay control data from the control unit 20, the display control unit26 processes the electronic book image data generated at this time fordisplay so as to further display the association information based onthe association information display control data and transmits theprocessed electronic book image data to the display unit 21.

As shown in FIG. 27, the display control unit 26 displays theassociation information title of each of the open associationinformation or the book title of each association electronic booktogether with the association comment on the electronic book image 27being displayed on the display unit 21 by matching the associationinformation title or the book title and the association comment with thetag TG instructed by the user.

Thus, the control unit 20 can notify the user of the tag TG expressingthe contents of the desired part and various kinds of associationinformation associated with the desired part together with desired part(that is, the desired part displayed in the emphasis manner) via theelectronic book image 27 being displayed on the display unit 21.

That is, when the control unit 20 displays the desired part in theemphasis manner in the electronic book image 27 being displayed on thedisplay unit 21 and there is the open association information associatedwith the desired part, the control unit 20 can inform the user whichassociation electronic book exists using the book title on theelectronic book image 27.

Moreover, when the control unit 20 displays the desired part in theemphasis manner in the electronic book image 27 being displayed on thedisplay unit 21 and there is the association electronic book associatedwith the desired part, the control unit 20 can notify the user of theexistence of the association electronic book by the book title on theelectronic book image 27.

Furthermore, when control unit 20 displays the desired part in theemphasis manner in the electronic book image 27 being displayed on thedisplay unit 21 and there is the association comment associated with thedesired part, the control unit 20 can exhibit the association comment onthe electronic book image 27.

When the display control unit 26 displays the association informationtitle of each of the open association information on the electronic bookimage 27 being displayed, the display control unit 26 generates titledisplay region information indicating the display region of theassociation information title for each association information title byusing the coordinates of the pixel position of the display surface ofthe display unit 21. Then, the display control unit 26 transmits boththe title display region information and the corresponding associationinformation title to the control unit 20.

When the display control unit 26 displays the book title of eachassociation electronic book on the electronic book image 27 beingdisplayed, the display control unit 26 also generates title displayregion information indicating the display region of the book title foreach book title by using the coordinates of the pixel position of thedisplay surface of the display unit 21. Then, the display control unit26 transmits both the title display region information and thecorresponding book title to the control unit 20.

While the association information title is displayed, the control unit20 specifies the network address corresponding to the associationinformation title based on the association information title and theassociation information supply data transmitted together with the titledisplay region information from the display control unit 26.

While the association information title is displayed, the control unit20 maintains the title display region information of the associationinformation title transmitted from the display control unit 26 bymatching the title display region information with the network addressspecified by the association information title.

While the book title is displayed, the control unit 20 specifies thebook identification information, the page number and the desired partposition information corresponding to the book title based on the booktitle and the association information supply data transmitted togetherwith the title display region information from the display control unit26.

When the book title is displayed, the control unit 20 maintains thetitle display region information of the book title transmitted from thedisplay control unit 26 by matching the title display region informationwith the book identification information, the page number, and thedesired part position information specified by the book title.

Therefore, the user taps the surface of the touch panel during thedisplay of the association information title or the book title on theelectronic book image 27 being displayed on the display unit 21, thecontrol unit 20 compares the touch position by the tap operation to thedisplay region indicated by the title display region information.

As a consequence, when the control unit 20 detects that the displayregion of the association information title is tapped, the control unit20 determines that the association information title is instructed bythe tap operation.

At this time, the control unit 20 detects the network address matchedwith the title display region information based on the title displayregion information indicating the tapped display region.

Then, the control unit 20 generates the information request data used togive a request of the open association information of the instructedassociation information title and transmits both the generatedinformation request data and the detected network address to thetransmission unit 23.

Based on the network address transmitted from the control unit 20, thetransmission unit 23 transmits the information request data transmittedfrom the control unit 20 to the information supply apparatus (not shown)publicizing the open association information of the instructedassociation information title via the network 13.

As a consequence, the reception unit 24 receives the open associationinformation and transmits the open association information to thecontrol unit 20, when the open association information is transmittedfrom the information supply apparatus via the network 13 in response tothe reception of the information request data.

When the control unit 20 receives the open association information fromthe reception unit 24, the control unit 20 transmits the openassociation information to the display control unit 26. Then, when thedisplay control unit 26 receives the open association information fromthe control unit 20, the display control unit 26 changes the openassociation information into the electronic book image data generated atthis time and transmits the electronic book image data to the displayunit 21.

Thus, the display control unit 26 changes the electronic image data intothe electronic book image and displays the open association informationon the display unit 21. Thus, when the association information title isinstructed on the electronic book image being displayed on the displayunit 21, the control unit 20 can change the electronic image data intothe electronic book image and displays the open association informationassociated with the desired part in the electronic book image to exhibitthe open association information to the user.

When the user executes a predetermined operation in the state where theopen association information is displayed on the display unit 21, thecontrol unit 20 controls the display control unit 26 in response to thepredetermined operation, switches the information into the openassociation information on the display unit 21, and again displays theelectronic book image having been displayed before display change.

When the control unit 20 compares the touch position of the tapoperation to the display region indicated by the title display regioninformation and detects that the display region of the book title istapped, the control unit 20 determine that the book title is instructedby the tap operation.

At this time, based on the title display region information indicatingthe tapped display region, the control unit 20 detects the bookidentification information, the page number, and the desired partposition information matched with the title display region information.

Based on the detected book identification information, the control unit20 reads the electronic book data of the electronic book associated withthe book title instructed at this time from the storage unit 25. Thecontrol unit 20 transmits the electronic book data together with thepage number and the desired part position information detected at thistime to the display control unit 26.

That is, the control unit 20 transmits, to the display control unit 26,the electronic book data of the association electronic book togetherwith the page number and the desired part position informationinstructing the page of the text including the desired part with thedetected identical keyword and the position of the desired part in thetext.

In the following description, a one-page text including the desired partwith the detected identical keyword in the association electronic bookis referred to as an association page and the desired part with thedetected identical keyword is also referred to as an association desiredpart.

When the display control unit 26 receives the page number and thedesired part position information together with the electronic book datafrom the control unit 20, the display control unit 26 generates theelectronic book image data of the page instructed with the page numberbased on the electronic book data.

The display control unit 26 processes the electronic book image data soas to display the desired part instructed with the desired part positioninformation in the emphasis manner and transmits the processedelectronic book image data to the display unit 21.

Thus, the display control, unit 26 changes the electronic image datainto the electronic book image being displayed on the display unit 21and displays, as an association electronic book image, a part includingat least the association desired part in the association page of theassociation electronic book.

At this time, the display control unit 26 displays the associationdesired part in the emphasis manner in the association electronic bookimage being displayed on the display unit 21. When there is the desiredpart as well as the association desired part in the associationelectronic book image, the display control unit 26 displays the otherdesired part in the emphasis manner. In this case, the display controlunit 26 displays the association desired part in the emphasis manner ina display state different from that of the other desired part.

Thus, when the book title corresponding to the desired part instructedby the electronic book image being displayed on the display unit 21, thecontrol unit 20 can switch the image into the electronic book image ofthe book title and can display and exhibit the association electronicbook image including the association desired part of the associationelectronic book associated with the desired part.

At this time, the control unit 20 can confirm the association desiredpart actually associated to the contents of the desired part in theassociation electronic book image by emphasizing and displaying theassociation desired part in the association electronic book imageassociated with the desired part on the electronic book image.

When the user executes a predetermined operation in the state where theassociation electronic book image is displayed on the display unit 21,the control unit 20 also controls the display control unit 26, switchesthe image into the association electronic book image on the display unit21, and displays the electronic book image having been displayed beforethe display switch again.

When the display region of the desired part is tapped once in theelectronic book image 27 being displayed on the display unit 21, asdescribed above, the control unit 20 controls the display control unit26 in response to the tap operation and displays the tag TG so as tocorrespond to the desired part.

Accordingly, there is a plurality of desired part selected in theelectronic book image 27 being displayed on the display unit 21, thecontrol unit 20 can display the plurality of desired parts bycorresponding to the tags TG thereof and can simultaneously exhibit thetags TG of the respective desired parts.

When the display region of the tag TG is tapped once in the electronicbook image 27 being displayed on the display unit 21, as describedabove, the control unit 20 controls the display control unit 26 tocorrespond to the tag TG in response to the tap operation and displaysthe association information title, the book title, or the like.

Accordingly, when there is the plurality of desired parts selected inthe electronic book image 27 being displayed on the display unit 21, thecontrol unit 20 can display the plurality of desired parts bycorresponding to the association information titles or the like of theplurality of desired parts of the respective tags TG and cansimultaneously exhibit the association information titles or the like ofthe respective tags TG.

For example, when the tag TG is displayed on the electronic book image27 and the user executes a tap operation continuously twice to instructthe tag TG, the control unit 20 controls the display control unit 26 inresponse to the tap operation. At this time, the control unit 20 deletesthe tag TG instructed by the twice tap operation from the electronicbook image 27.

For example, when the tag TG and the association information title orthe like corresponding to the tag TG are displayed on the electronicbook image 27 and the user executes a tap operation continuously twiceto instruct the tap TG, the control unit 20 controls the display controlunit 26 in response to the tap operation.

At this time, the control unit 20 deletes the tag TG twice instructed bythe tap operation and the association information title or the likecorresponding to the tag TG from the electronic book image 27 en bloc.

For example, when the plurality of tags TG is displayed on theelectronic book image 27 and user taps a region other than the displayregions of the tags TG continuously twice, the control unit 20 controlsthe display control unit 26 in response to the tap operation.Accordingly, the control unit 20 deletes all of the tags TG from theelectronic book image 27 en bloc.

For example, when the plurality of tags TG and the associationinformation titles or the like corresponding to the plurality of tags TGare displayed on the electronic book image 27 and the user taps a regionother than the display regions of the tags TG or the associationinformation titles or the like continuously twice, the control unit 20controls the display control unit 26. Accordingly, the control unit 20deletes all of the tags TG and all of the association information titlesor the like from the electronic book image 27 en bloc.

Thus, the control unit 20 can display the tag TG, the associationinformation title, or the like on the electronic book image 27 and candelete the tag TG, the association information title, or the like enbloc by a simple operation.

Accordingly, when the text in the electronic book image 27 is read or aphoto image or an illustration image is viewed, the control unit 20 caneasily prevent the tag TG, the association information title, or thelike from being interfered.

2-2-2. Index Generation Process

Next, an index generation process of generating an individual index of auser for an electronic book will be described. When the electronic bookimage 27 is displayed on the display unit 21 in response to a requestfor display the electronic book, as described above, the control unit 20can hierarchically generate an individual index of the user for theelectronic book in response to user selection of the desired part.

In effect, the control unit 20 executes the index generation processwhen a key operation or a tap operation is executed to select anelectronic book for which an index is generated and the request forgenerating an index is given. At this time, the control unit 20transmits, from the storage unit 25, reads the electronic book data ofthe selected electronic book and transmits the electronic book data tothe display control unit 26.

Based on the electronic book data, the display control unit 26 generatesthe electronic book image data corresponding to one page. Then, thedisplay control unit 26 transmits, to the display unit 21, theelectronic book image data as data of an image of which at least a partcan be displayed in accordance with, for example, the size or resolutionof the display surface of the display unit 21.

Thus, as described above with reference to FIG. 4, the display controlunit 26 displays at least a part of the electronic book image formed ofa one-page text which is based on the electronic image data across theentire display surface of the display unit 21.

When the user executes a slide operation on the electronic book image toinstruct the desired part in this state, the control unit 20 thedetermination result of the kind of slide operation described above andthe touch position information indicating all of the touch positionsdetected during the slide operation to the selection unit 28.

At this time, the control unit 20 also generates the regioncorrespondence text data and transmits the generated regioncorrespondence text data and the book attribute data to the selectionunit 28.

The selection unit 28 executes the selection process, as describedabove, and selects the instruction estimated part from the text of thetext of the display range or one page. Then, the selection unit 28generates the instruction estimated part data indicating the instructionestimated part and transmits both the generated instruction estimatedpart data and the book attribute data to the acquisition unit 29.

At this time, the control unit 20 extracts the book identificationinformation from the book attribute data of the electronic book selectedfor generating the index thereof in response to the instruction of thedesired part.

The control unit 20 adds the book identification information to the textdata corresponding to all of the pages of the electronic book for whichthe index is generated. Then, the control unit 20 transmits, to theacquisition unit 29, the text data (hereinafter, also referred to aswhole text data) corresponding to all of the pages to which the bookidentification information is added.

When the acquisition unit 29 receives all of the text data from thecontrol unit 20, the acquisition unit 29 transmits all of the text datato the natural language processing block 30 and asks the naturallanguage processing block 30 to process all of the text data.

Thus, in the natural language processing block 30, the morpheme analysisunit 30A analyzes the morphemes of the text (hereinafter, also referredto as a whole book text) corresponding to all of the pages which isbased on all of the text data, as described above, and generates themorpheme analysis result data indicating the analysis result. Then, themorpheme analysis unit 30A transits both the morpheme analysis resultdata and all of the text data to the syntax analysis unit 30B.

As described above, based on the morpheme analysis result data, thesyntax analysis unit 30B analyzes the syntax of the whole book textwhich is based on all of the text data and generates the syntax analysisresult data indicating the analysis result.

Then, the syntax analysis unit 30B returns, to the acquisition unit 29,the morpheme analysis part data and the syntax analysis part data aswhole passage analysis result data which indicates the processing resultof the natural language processing on the whole book text together withall of the text data.

When the acquisition unit 29 receives the whole passage analysis resultdata and all of the text data from the natural language processing block30, the acquisition unit 29 temporarily maintains the whole passageanalysis result data and all of the text data and transmits the wholepassage analysis result data and all of the text data to the retrievalunit 66.

When the acquisition unit 29 receives the instruction estimated partdata and the book attribute data from the selection unit 26, theacquisition unit 29 specifies information indicating the analysisresults of the morpheme analysis and the syntax analysis of theinstruction estimated part from the whole passage analysis result datatemporarily maintained based on the instruction estimated part data.

The acquisition unit 29 cuts out, as the estimated part analysis resultdata, the specified information indicating the analysis results of themorpheme analysis and the syntax analysis of the instruction estimatedpart from the whole passage analysis result data. Then, the acquisitionunit 29 transits the estimated part analysis result data together withthe instruction estimated part data and the book attribute data to thespecifying unit 33.

As described above, based on the estimated part analysis result datatransmitted from the acquisition unit 29, the specifying unit 33specifies the desired part selected by the user in the instructionestimated part which is based on the instruction estimated part datatransmitted from the acquisition unit 29.

The specifying unit 33 generates the desired part data indicating thespecified desired part based on the instruction estimated part data andtransmits both the generated desired part data and the book attributedata to the registration unit 34.

The specifying unit 33 generates the desired part analysis result dataindicating the analysis result of the desired part based on the bookattribute data and the estimated part analysis result data and transmitsthe generated desired part analysis result data to the detection unit35.

Here, when the desired part data and the book attribute data aretransmitted from the specifying unit 33, the registration unit 34appropriately registers the electronic book with the selected desiredpart in the book registration table DT1 of the book registrationdatabase in the storage unit 25, as described above.

At this time, the registration unit 34 registers the desired partselected from the electronic book in the desired part registration tableDT2 of the book registration database in the storage unit 25, asdescribed above.

When the registration is completed, the registration unit 34 adds, tothe desired part data, the desired part identification informationissued for the desired part and the book identification information andthe book title of the electronic book with the selected desired part andgenerates registration desired part data indicating, the registereddesired part. Then, the registration unit 34 transmits the registereddesired part data to the index generation unit 67.

When the detection unit 35 receives the desired part analysis resultdata from the specifying unit 33, the detection unit 35 detects a wordimportant to the understanding of the contents of the desired part fromthe desired part in accordance with the same method as that of thekeyword detection process described above based on the desired partanalysis result data.

When the detection unit 35 detects the word important to theunderstanding of the contents of the desired part from the desired part,the detection unit 35 also detects the meaning of the detected word(hereinafter, also referred to as a detection word).

The detection unit 35 extracts the detection words (plurality ofcharacters expressing a word including single or plurality of morphemes)from the desired part analysis result data without repetition andextracts the meaning word expressing the meaning of the detection wordwithout repetition.

Here, the detection unit 35 extracts, from the desired part analysisresult data, the book identification information, the page number of apage with the desired part present in the whole book text, and the frontcharacter position information indicating the position of the frontcharacter of the desired part.

The detection unit 35 stores the book identification information, thepage number, and the front character position information, generates theidentification information retrieval request data used to give a requestfor retrieving the desired part identification of the desired part, andtransmits the generated identification information retrieval requestdata to the retrieval unit 66.

Then, the retrieval unit 66 retrieves and reads the desired partidentification information used to give the request for the retrievalfrom the storage unit 25 based on the identification informationretrieval request data transmitted from the detection unit 35.

The retrieval unit 66 stores the retrieved desired part identificationinformation together with the book identification information, the pagenumber, and the front character position information of theidentification information retrieval request data, generatesidentification information notification data used to give a notificationof the retrieved desired part identification information, and returnsthe identification information notification data to the detection unit35.

At this time, when the detection unit 35 receives the identificationinformation notification data from the retrieval unit 66, the detectionunit 35 confirms whether the desired part identification informationused to give the request for retrieval can be obtained based on the bookidentification information, the page number, and the front characterposition information stored in the identification informationnotification data.

As a result, when the desired part identification information used togive the request for retrieval is stored in the identificationinformation notification data, the detection unit 35 extracts thedesired part identification information from the identificationinformation notification data.

At this time, the detection unit 35 stores both the detection word andthe desired part identification information for each detection wordextracted from the desired part analysis result data without repetitionand generates word detection data indicating the detection result of thedetection word. Then, the detection unit 35 transmits the word detectiondata to the retrieval unit 66.

At this time, the detection unit 35 stores both the meaning word and thedesired part identification information for each meaning word extractedfrom the desired part analysis result data without repetition andgenerates meaning word detection data indicating the detection result ofthe meaning word. Then, the detection unit 35 transmits the meaning worddetection data to the retrieval unit 66.

When the retrieval unit 66 receives the whole passage analysis resultdata and all of the text data from the acquisition unit 29, theretrieval unit 66 temporarily maintains the whole passage analysisresult data and all of the text data. When the retrieval unit 66receives the word detection data from the detection unit 35, theretrieval unit 66 extracts the detection word and the desired partidentification information from the word detection data.

Then, based on the detection word, the retrieval unit 66 retrieves allof the detection words and the words (including the shame characterstring) having the same structure from the whole book text, which isbased on all of the text data, and detects the positions of the detectedwords in the whole book text.

At this time, the retrieval unit 66 also retrieves the detection wordsdetected from the desired part by the detection unit 35 and detects thepositions of the detection words in the whole book text. In thefollowing description, the word having the same structure as that of thedetection word is also referred to as an identically structured word. Inthe following description, the position of a word having the samestructure word is also referred to as an identical structure wordposition.

In effect, the retrieval unit 66 detects the identical structure wordposition of the identical structure word in the whole book text as thepage number of a page where the identical structure word is present, thefront character position information (row number and column number)indicating the position of the front character of the identicalstructure word, and the character number of identical structure word.

When the retrieval unit 66 receives the meaning word detection data fromthe detection unit 35, the retrieval unit 66 extracts the meaning wordand the desired part identification information from the meaning worddetection data.

Based on the meaning word and the meaning word corresponding to variouswords obtained based on the whole passage analysis result data, theretrieval unit 66 retrieves, from the whole book text, all of the wordswhich have a structure different from that of the detection word and thesame meaning as that of the detection word.

That is, the retrieval unit 66 retrieves, from the whole book text, allof the words (having the same meaning as that of the detection word), towhich the meaning word identical to the meaning word expressing themeaning of the detection word is matched, excluding the identicalstructure word. Then, the retrieval unit 66 detects the position of thedetected word in the whole book text.

In the following description, the word that has a structure differentfrom that of a word (that is, the detection word) and the same meaningas that of the detection word is also referred to as an identicalmeaning word. Moreover, in the following description, the position ofthe identical meaning word in the whole book text is also referred to asan identical meaning word position.

In effect, the retrieval unit 66 also detects the identical meaning wordposition of the identical meaning word in the whole book text as thepage number of a page where the identical meaning word is present, thefront character position information (row number and column number)indicating the position of the front character of the identical meaningword, and the character number of identical meaning word.

Thus, based on the detection word, the retrieval unit 66 retrieves theidentical structure word from the whole book text for each detectionword detected from the desired part without repetition by the detectionunit 35 and detects the identical structure word position of theidentical structure word.

Moreover, the retrieval unit 66 retrieves the identical meaning wordfrom the whole book text for each detection word detected from thedesired part without repetition by the detection unit 35 based on themeaning word and detects the identical meaning word position of theidentical meaning word.

The retrieval unit 66 stores the detection word, an identical structureword position information indicating the identical structure wordposition of the identical structure word retrieved with the detectionword, and the desired part identification information for each detectionword and generates identical structure word retrieval data indicatingthe retrieval result of the identical structure word.

Moreover, the retrieval unit 66 stores the meaning word, an identicalmeaning word position information indicating the identical meaning wordposition of the identical meaning word retrieved with the meaning word,and the desired part identification information for each meaning wordand generates identical meaning word retrieval data indicating theretrieval result of the identical meaning word.

Then, the retrieval unit 66 transmits the identical structure wordretrieval data and the identical meaning word retrieval data generatedfor each detection word to the index generation unit 67.

In this way, the control unit 20 allows the selection unit 28, theacquisition unit 29, the specifying unit 33, the detection unit 35, theregistration unit 34, and the retrieval unit 66 to perform the sameprocessing, whenever the user instructs the desired part on theelectronic book image being displayed on the display unit 21.

Whenever the index generation unit 67 receives the registration desiredpart data from the registration unit 34 during the index generationprocess, the index generation unit 67 temporarily maintains theregistration desired part data.

Whenever the index generation unit 67 receives the identical structureword retrieval data and the identical meaning word retrieval data foreach detection word from the retrieval unit 66 during the indexgeneration process, the index generation unit 67 temporarily also storesthe identical structure word retrieval data and the identical meaningword retrieval data of each detection word.

When the control unit 20 detects that the selection of the desired partfrom the electronic book for which the index is generated ends inresponse to a predetermined operation of the user, the control unit 20notifies the index generation unit 67 of the fact that the selection ofthe desired part ends.

When the index generation unit 67 is notified of the fact that theselection of the desired part ends from the control unit 20, the indexgeneration unit 67 extracts the desired part, the desired partidentification information, the book identification information, and thebook title from each registration desired part data temporarilymaintained at that time in response to the notification.

The index generation unit 67 generates a desired part list indicatingthe desired part together with the corresponding desired partidentification information in a sequence from the front side to the rearside of the whole book text.

The index generation unit 67 generates an index, which indicates theelectronic book for which the index is generated and the desired partselected from the electronic book, as a first hierarchical index whichis the highest layer of the indexes of the hierarchical structure, byadding the book identification information and the book title to thedesired part list.

Moreover, the index generation unit 67 extracts the desired partidentification information from the identical structure word retrievaldata and the identical meaning word retrieval data maintainedtemporarily up to the present time.

Based on the desired part identification information, the indexgeneration unit 67 classifies the identical structure word retrievaldata and the identical meaning word retrieval data for each desiredpart.

For example, the index generation unit 67 extracts the detection wordand the meaning word from the identical structure word retrieval dataand the identical meaning word retrieval data organized from one desiredpart and issues identification information used to individually identifythe detection words and the meaning words.

In the following description, the identification information used toindividually identify the detection words is referred to detection wordidentification information and the identification information used toindividually identify the meaning words is referred to meaning wordidentification information.

The index generation unit 67 displays the detection words detected fromthe desired part and the corresponding detection word identificationinformation and generates a detection word list which displays themeaning words detected based on the desired part and the correspondingmeaning word identification information after the detection words.

The index generation unit 67 adds the desired part identificationinformation to the detection word list and associates the detection wordlist with the desired part corresponding to the first hierarchical indexbased on the desired part identification information.

The index generation unit 67 generates an index, which indicates thedetection words detected from the desired part, the meaning wordsdetected based on the desired part, and the desired part, as a secondhierarchical index lower than the first hierarchical index, among theindexes of the hierarchical structure.

At this time, the index generation unit 67 processes each desired partin the first hierarchical index in the same way as the above-describedway and generates the second hierarchical index having the samestructure and associated with the desired part.

Subsequently, for example, the index generation unit 67 extracts theidentical structure word position information of each identicalstructure word from one piece of identical structure word retrieval dataamong the identical structure word retrieval data organized from onedesired part.

The index generation unit 67 generates an identical structure wordposition list which displays the identical structure word positioninformation in sequence from the identical structure word position onthe front side of the whole book text to the identical structure wordposition on the rear side of the whole book text.

The index generation unit 67 adds, to the identical structure wordposition list, the detection word used for retrieving the identicalstructure word and the detection word identification information of thedetection word and associates the identical structure word position listwith the detection word corresponding to the second hierarchical indexbased on the detection word identification information.

Thus, the index generation unit 67 generates an index, which indicatesthe detection words detected from the desired part and the identicalstructure word position of the identical structure word retrieved withthe detection word in the whole book text, as a third hierarchical indexlower than the first and second hierarchical indexes, among the indexesof the hierarchical structure.

At this time, the index generation unit 67 processes each detection wordin the second hierarchical index in the same way as the above-describedway and generates the third hierarchical index which has the sameconfiguration and is associated with the detection word.

For example, the index generation unit 67 extracts the identical meaningword position information of each identical meaning word from one pieceof identical meaning word retrieval data among the identical meaningword retrieval data organized from one desired part.

The index generation unit 67 generates an identical meaning wordposition list which sequentially displays the identical meaning wordposition information in the arrangement sequence from the identicalmeaning word position on the front side of the whole book text to theidentical meaning word position on the rear side of the whole book text.

The index generation unit 67 adds, to the identical meaning wordposition list, the meaning word used for retrieving the identicalmeaning word and the meaning word identification information of themeaning word and associates the identical meaning word position listwith the meaning word corresponding to the third hierarchical indexbased on the meaning word identification information.

Thus, the index generation unit 67 also generates an index, whichindicates the meaning words detected from the desired part and theidentical meaning word position of the identical meaning word retrievedwith the meaning word in the whole book text, as a third hierarchicalindex lower than the first hierarchical index by one layer, among theindexes of the hierarchical structure.

At this time, the index generation unit 67 processes each meaning wordin the second hierarchical index in the same way as the above-describedway and generates the third hierarchical index which has the sameconfiguration and is associated with the meaning word.

Thus, when the index generation unit 67 generates the first to thirdhierarchical indexes, the index generation unit 67 transmits thegenerated first to third hierarchical indexes as first to thirdhierarchical index data to the storage unit 25. The index generationunit 67 stores the first to third hierarchical index data in the storageunit 25.

When the first to third hierarchical index are completely generated andstored, the index generation unit 67 notifies the control unit 20 of thefact that the first to third hierarchical index are completely generatedand stored. Then, the control unit 20 ends the index generation processperformed with each circuit unit so that the first to third hierarchicalindexes can be used.

For example, when the user executes a predetermined operation to selectthe electronic book, which has generated the individual index of theuser, so as to be displayed and gives a request for display of theindex, the control unit 20 stores the book identification information ofthe electronic book and generates first hierarchical index request datato give a request of the first hierarchical index. The control unit 20transmits the first hierarchical index request data to the retrievalunit 66.

When the retrieval unit 66 receives the first hierarchical index requestdata from the control unit 20, the retrieval unit 66 reads the firsthierarchical index request data including the book identificationinformation from the storage unit 25 based on the book identificationinformation stored in the first hierarchical index request data andtransmits the first hierarchical index request data to the control unit20.

When the control unit 20 receives the first hierarchical index data fromthe retrieval unit 66, the control unit 20 extracts the book title andthe desired part list from the first hierarchical index data.

The control unit 20 generates first hierarchical index image data basedon the book title and the desired part list. Then, the control unit 20transmits the first hierarchical index image data to the display controlunit 26.

When the display control unit 26 receives the first hierarchical indeximage data from the control unit 20, the display control unit 26transmits the first hierarchical index image data to the display unit21. Thus, the display control unit 26 displays a first hierarchicalindex image 70 shown in FIG. 28 on the display unit 21 based on thefirst hierarchical index image data.

At this time, for example, a book title 71 is displayed on the upperside of the first hierarchical index image 70 and a plurality of desiredparts arranged in the desired part list is displayed on the lower sideof the book title 71 in an image vertical direction.

Then, the control unit 20 can give a notification of the desired partalready selected in the electronic image to be displayed, so as toconfirm the desired part by the first hierarchical index image 70.

At this time, the display control unit 26 generates desired part displayregion information indicating the display region of the desired part inthe first hierarchical index image 70 being displayed on the displayunit 21 with the coordinates of the pixel position of the displaysurface of the display unit 21.

The display control unit 26 transmits the desired part display regioninformation of the desired part together with the desired partidentification information of the desired part to the control unit 20.

During the display of the first hierarchical index image 70, the controlunit 20 maintains the desired part display region information and thedesired part identification information of the desired part transmittedfrom the display control unit 26 by matching the desired part displayregion information with the desired part identification information.

When the user taps the surface of the touch panel during the display ofthe first hierarchical index image 70, the control unit 20 compares thetouch position of the tap operation to the display region of the desiredpart indicated by the desired part display region information.

As a consequence, when the control unit 20 detects that the user tapsthe display region of the desired part, the control unit 20 determinesthat the desired part is instructed by the tap operation.

At this time, the control unit 20 detects the desired partidentification information matched with the desired part display regioninformation based on the desired part display region informationindicating the tapped display region.

The control unit 20 stores the desired part identification information(that is, the desired part identification information of the instructeddesired part) detected in response to the tap operation and generatessecond hierarchical index request data used to give a request of thesecond hierarchical index data. Then, the control unit 20 transmits thesecond hierarchical index request data to the retrieval unit 66.

When the retrieval unit 66 receives the second hierarchical indexrequest data from the control unit 20, the retrieval unit 66 reads thesecond hierarchical index data including the desired part identificationinformation from the storage unit 25 based on the desired partidentification information stored in the second hierarchical indexrequest data and transmits the second hierarchical index data to thecontrol unit 20.

When the control unit 20 receives the second hierarchical index datafrom the retrieval unit 66, the control unit 20 extracts the detectionword list from the second hierarchical index data. Moreover, the controlunit 20 generates second hierarchical index image data based on thedetection word list. Then, the control unit 20 transmits the secondhierarchical index image data to the display control unit 26.

When the display control unit 26 receives the second hierarchical indeximage data from the control unit 20, the display control unit 26transmits the second hierarchical index image data to the display unit21. Thus, the display control unit 26 displays a second hierarchicalindex image 71 shown in FIG. 29 on the display unit 21 based on thesecond hierarchical index image data.

At this time, in the second hierarchical index image 71, for example,single or a plurality of detection words detected from the correspondingdesired part and the meaning words detected based on the desired partare sequentially displayed in the arrangement sequence of the detectionword list in the image vertical direction.

Thus, the control unit 20 can give a notification of the detection wordsdetected based on the instructed desired part and the meanings of thedetection words, so as to confirm the detection words and the meaningsof the detection words by the second hierarchical index image 71.

At this time, the display control unit 26 generates word display regioninformation indicating the display region of the detection word in thesecond hierarchical index image 71 being displayed on the display unit21 with the coordinates of the pixel position of the display surface ofthe display unit 21. Then, the display control unit 26 transmits theword display region information of the detection word together with thedetection word identification information of the detection word to thecontrol unit 20.

At this time, the display control unit 26 also generates meaning worddisplay region information indicating the display region of the meaningword in the second hierarchical index image 71 being displayed on thedisplay unit 21 with the coordinates of the pixel position of thedisplay surface of the display unit 21. Then, the display control unit26 transmits the meaning word display region information of the meaningword together with the meaning word identification information of themeaning word to the control unit 20.

During the display of the second hierarchical index image 71, thecontrol unit 20 maintains the word display region information and thedetection word identification information of the detection wordstransmitted from the display control unit 26 by matching the worddisplay region information with the detection word identificationinformation.

Moreover, during the display of the second hierarchical index image 71,the control unit 20 maintains the meaning word display regioninformation and the meaning word identification information of themeaning words transmitted from the display control unit 26 by matchingthe meaning word display region information with the meaning wordidentification information.

When the user taps the surface of the touch panel during the display ofthe second hierarchical index image 71, the control unit 20 compares thetouch position of the tap operation to the display region of thedetection word indicated by the word display region information. At thistime, the control unit 20 also compares the touch position of the tapoperation to the display region of the meaning word indicated by themeaning word display region information.

As a consequence, for example, when the control unit 20 detects that theuser taps the display region of the detection word, the control unit 20determines that the detection word is instructed by the tap operation.

At this time, the control unit 20 detects the detection wordidentification information matched with the word display regioninformation based on the word display region information indicating thetapped display region.

The control unit 20 stores the detection word identification information(that is, the detection word identification information of theinstructed detection word) detected in response to the tap operation andthe desired part identification information obtained based on the secondhierarchical index data and generates third hierarchical index requestdata used to give a request of the third hierarchical index data. Then,the control unit 20 transmits the third hierarchical index request datato the retrieval unit 66.

When the retrieval unit 66 receives the third hierarchical index requestdata from the control unit 20, the retrieval unit 66 reads the thirdhierarchical index data including the detection word identificationinformation and the desired part identification information from thestorage unit 25 based on the detection word identification informationand the desired part identification information stored in the thirdhierarchical index request data. Then, the retrieval unit 66 transmitsthe third hierarchical index data to the control unit 20.

When the control unit 20 receives the third hierarchical index data fromthe retrieval unit 66, the control unit 20 extracts the detection wordand the identical structure word position list from the thirdhierarchical index data.

Moreover, the control unit 20 generates third hierarchical index imagedata based on the detection words and the identical structure wordposition list. Then, the control unit 20 transmits the thirdhierarchical index image data to the display control unit 26.

When the display control unit 26 receives the third hierarchical indeximage data from the control unit 20, the display control unit 26transmits the third hierarchical index image data to the display unit21. Thus, the display control unit 26 displays a third hierarchicalindex image 72 shown in FIG. 30 on the display unit 21 based on thethird hierarchical index image data.

At this time, for example, the detection word instructed by the user isdisplayed on the upper side of the third hierarchical index image 73.For example, in the third hierarchical index image 73, the page numberand the front character position information indicating the identicalstructure word position in the whole book text of the identicalstructure word retrieved with the detection word are displayed on thelower side of the detection words which are displayed in the arrangementsequence of the identical structure word position list in the imagevertical direction.

Thus, the control unit 20 can give a notification of the identicalstructure word position of the identical structure word in theelectronic book retrieved with the instructed detection word, so as toconfirm the identical structure word position by the third hierarchicalindex image 72.

At this time, the display control unit 26 generates position displayregion information indicating the display regions of the page number andthe front character position information indicating the identicalstructure word position of the identical structure word in the thirdhierarchical index image 72 being displayed on the display unit 21 withthe coordinates of the pixel position of the display surface of thedisplay unit 21.

Then, the display control unit 26 transmits the position display regioninformation of the identical structure word together with the identicalstructure word position information of the identical structure word tothe control unit 20.

During the display of the third hierarchical index image 72, the controlunit 20 maintains the position display region information and theidentical structure word position information of the identical structureword transmitted from the display control unit 26 by matching theposition display region information with the identical structure wordposition information.

When the user taps the surface of the touch panel during the display ofthe third hierarchical index image 72, the control unit 20 compares thetouch position of the tap operation to the display region of theidentical structure word position of the identical structure wordindicated by the position display region information.

As a consequence, for example, when the control unit 20 detects that theuser taps the display region of the identical structure word position ofthe identical structure word, the control unit 20 determines that theidentical structure word position of the identical structure word isinstructed for displaying the identical structure word by the tapoperation.

At this time, the control unit 20 reads, from the storage unit 25, theelectronic book data of the electronic book selected so as to bedisplayed and transmits the electronic book data to the display controlunit 26.

At this time, the control unit 20 generates emphasis display controldata used to perform control of displaying the identical structure wordin the emphasis manner based on the identical structure word positioninformation of the identical structure word at the identical structureword position instructed to be displayed. Then, the control unit 20transmits the generated emphasis display control data to the displaycontrol unit 26.

When the display control unit 26 receives the electronic book data andthe emphasis display control data from the control unit 20, the displaycontrol unit 26 generates electronic book image data of a page includingthe identical structure word position of the instructed identicalstructure word based on the electronic book data.

Moreover, the display control unit 26 processes the electronic bookimage data based on the emphasis display control data and transmits theprocessed electronic book image data to the display unit 21. Thus, thedisplay control unit 26 displays the electronic book image on thedisplay unit 21 based on the electronic book image data so that theidentical structure word at the instructed identical structure wordposition falls within the display range and displays the identicalstructure word in the emphasis manner.

Thus, the control unit 20 can display the electronic book image byjumping to an electronic book image including the part associated withthe desired part already selected by the user in the electronic bookbased on the individual index of the user.

Even when the meaning word is instructed on the second hierarchicalindex image 71, the control unit 20 displays the third hierarchicalindex image corresponding to the meaning word.

When the identical meaning word position of the identical meaning wordis instructed on the third hierarchical index image, the control unit 20displays the electronic book image of a page where the identical meaningword is located and displays the identical meaning word included in thetext in the electronic book image in the emphasis manner.

Thus, when a request for displaying the electronic book is given, thecontrol unit 20 can display the first to third hierarchical index images70 to 72 to view the contents of the electronic book just like the userfirst views a front page of a paper novel.

When the control unit 20 generates the individual index of the user forthe electronic book, the control unit 20 can jump to a desired pageusing the first to third hierarchical index images 70 to 72 so that theuser starts to read the electronic book. This is because there is a highpossibility that the user reads the electronic book at least once whenthe index is generated.

The control unit 20 can permit easily searching for a portion of aphrase, a clause, or the like associated with the desired part in thewhole book text by activating a jump function of jumping to a desiredpage of the electronic book using the first to third hierarchical indeximages 70 to 72. In the following description, the region of a phrase, aclause, or the like associated with the desired part in the whole booktext is also referred to as an association portion.

Even when the control unit 20 displays the electronic book image of theelectronic book generating the individual index of the user and thedesired part is selected in the text of the electronic book image, asdescribed above, the control unit 20 displays the desired part in theemphasis manner.

Therefore, when the control unit 20 displays the electronic book imageof the electronic book generating the individual index of the user and,for example, the user reads the desired part, the control unit 20 caneasily cope with a request for reading the association portionassociated with the desired part in the electronic book.

In the association portion including the identical structure word in theelectronic book, the identical structure word having the same structureas that of the detection word detected from the desired part is includedand expressed.

Therefore, it is considered that relevance with the desired part usedfor retrieving the identical structure word is strong in the associationportion including the identical structure word in the electronic book.

The association portion including the identical meaning word in theelectronic book has the same meaning as the meaning of the detectionword detected from the desired part and includes the identical meaningword having a structure different from that of the detection word.

Accordingly, in the association portion including the identical meaningword in the electronic book, it is considered that relevance with thedesired part used for detecting the same meaning word is weaker than therelevance with the association portion including the desired portion andthe same structure word detected based on the desired portion.

Accordingly, when the control unit 20 displays the identical structureword or the identical meaning word in the emphasis manner, the controlunit 20 displays the identical structure word or the identical meaningword in the emphasis manner in different display states.

Thus, the control unit 20 can give a notification of the fact that thedegree of the relevance with the association portion including thedesired part and the identical structure word is different from thedegree of the relevance with the association portion including thedesired part and the identical meaning word.

The control unit 20 displays the identical structure word and theidentical meaning word in the emphasis manner in the different displaystates, as described above, and also displays the desired part in theemphasis manner in a display state different from the display states ofthe identical structure word and the identical meaning word.

Accordingly, when the display control 20 displays the identicalstructure word or the identical meaning word included in the desiredpart in the emphasis manner in the text of the electronic book imagebeing displayed on the display unit 21, the display control 20 caneasily permit the user to recognize which word is the identicalstructure word or the identical meaning word in the desired part.

Moreover, even when the user executes a predetermined operation toselect the electronic book generating the individual index of the userin order to display the electronic book, the control unit 20 does notdisplay the first hierarchical index image 70 in a case where the userdoes not give a request for displaying the index and gives a request fordisplaying the electronic book. Then, the control unit 20 displays theelectronic book image of the electronic book selected so as to bedisplayed on the display unit 21.

However, when the user executes a predetermined operation to give therequest for displaying the index in the state where the control unit 20displays the electronic book image of the electronic book generating theindividual index of the user, the control unit 20 performs theabove-described process, switches the image into the electronic bookimage, and displays the first hierarchical index image 70.

When the control unit 20 displays the first hierarchical index image 70,the control unit 20 then displays the second and third hierarchicalindex images 71 and 72 in response to the above-described operation ofthe user and finally displays the electronic book image of the pageincluding the identical structure word or the identical meaning word.

When the control unit 20 displays the first to third hierarchical indeximages 70 to 72 on the display unit 21, the control unit 20 returns thedisplay on the display unit 21 to the immediately previous display (thatis, the display immediately before the display of the first to thirdhierarchical index images 70 to 72) in response to a predeterminedoperation of the user.

For example, only when the control unit 20 returns the display to thedisplay of the first hierarchical index image 70 without displaying theelectronic book image in response to the request for displaying theelectronic book, for example, the control unit 20 displays theelectronic book image of the first page of the electronic book.

Accordingly, even when the control unit 20 displays the first to thirdhierarchical index images 70 to 72, the control unit 20 returns thedisplay to the immediately previous display and the user can instructthe desired part, the detection work, or the meaning word again.

Even when the control unit 20 performs the index generation process, thecontrol unit 20 detects the keyword, generates the tag, registers thekeyword or the tag, and retrieves the association information inresponse to the selection of the desired part, as in the case where thedesired part is selected without performing the index generationprocess.

2-2-3. Link Generation Process

Next, a link generation process will be described in which a link of theassociation portion associated with the desired part is generated in thewhole book text of the electronic book.

When the control unit 20 displays the electronic book image 27 on thedisplay unit 21 in response to the request for the electronic book, asdescribed above, the control unit 20 can also generate a link of theassociation portion associated with the desired part in the electronicbook in response to the user selection of the desired part.

In effect, when the user executes a key operation or a tap operation toselect the electronic book, in which a link is scheduled to begenerated, and give a request for generating a link, the control unit 20performs the link generation process. At this time, the control unit 20allows the display control unit 26 to display at least a part of theelectronic book image on the display unit 21, as in the above-describedindex generation process.

When the desired part is instructed on the electronic book image, thecontrol unit 20 generates the region correspondence text data, asdescribed above, and transmits both the generated region correspondencetext data and the book attribute data to the selection unit 28.

The control unit 20 generates whole text data corresponding to theelectronic book, in which a link is scheduled to be generated, andtransmits the generated whole text data to the acquisition unit 29.

Thus, the selection unit 28 performs the same processes as thoseperformed in the index generation process described above, selects theinstruction estimated part from the text of the text of the displayrange or one page, and generates the instruction estimated part dataindicating the instruction estimated part. Then, the selection unit 28transmits both the instruction estimated part data and the bookattribute data to the acquisition unit 29.

The acquisition unit 29 performs the same processes as those performedin the index generation process described above, transmits all of thetext data to the natural language processing block 30, and gives arequest for performing the natural language processing on all of thetext data.

Thus, the natural language processing block 30 performs the sameprocesses as those performed in the index generation process describedabove, analyzes all of the text data, generates whole passage analysisresult data indicating the analysis result, and transmits both the wholepassage analysis result data and the generated whole text data to theacquisition unit 29.

Accordingly, the acquisition unit 29 temporarily maintains the wholepassage analysis result data and all of the text data transmitted fromthe natural language processing block 30 and transmits the whole passageanalysis result data and all of the text data to the retrieval unit 66.

When the acquisition unit 29 receives the instruction estimated partdata and the book attribute data from the selection unit 26, theacquisition unit 29 specifies information indicating the analysisresults of the morpheme analysis and the syntax analysis from thetemporarily maintained whole passage analysis result data and cuts outthe estimated part analysis result data. Then, the acquisition unit 29transmits the estimated part analysis result data together with theinstruction estimated part data and the book attribute data to thespecifying unit 33.

At this time, the specifying unit 33 also performs the same processes asthose performed in the index generation process described above andspecifies the desired part selected by the user in the instructionestimated part, which is based on the instruction estimated part data,based on the estimated part analysis result data.

Moreover, the specifying unit 33 generates the desired part dataindicating the desired part based on instruction estimated part data andtransmits both the desired part data and the book attribute data to theregistration unit 34.

At this time, the specifying unit 33 generates desired part analysisresult data indicating the analysis result of the desired part based onthe book attribute data and the estimated part analysis result data andtransmits the generated desired part analysis result data to thedetection unit 35.

Here, when the registration unit 34 receives the desired part data andthe book attribute data from the specifying unit 33, the registrationunit 34 performs the same processes as those performed in the indexgeneration process described above and registers the electronic bookwith the selected desired part in the book registration table DT1 in thestorage unit 25.

At this time, the registration unit 34 also registers the desired partselected from the electronic book in the desired part registration tableDT2 of the book registration database in the storage unit 25.

On the other hand, when the detection unit 35 receives the desired partanalysis result data from the specifying unit 33, the detection unit 35performs the same processes as those performed in the index generationprocess described above. When the detection unit 35 detects thedetection words from the desired part based on the desired part analysisresult data, the detection unit 35 also detects the meanings of thedetection words.

Moreover, the detection unit 35 extracts the detection words withoutrepetition from the desired part analysis result data and also extractsthe meaning words expressing the meanings of the detection words withoutrepetition. Furthermore, the detection unit 35 acquires the desired partidentification information used to identify the desired part used fordetecting the detection words by the retrieval unit 66.

At this time, the detection unit 35 stores the detection words togetherwith the book identification information and the desired partidentification information for each of the detection words extractedwithout repetition from the desired part analysis result data andgenerates the word detection data indicating the detection result of thedetection words. Then, the detection unit 35 transmits the worddetection data to the retrieval unit 66.

At this time, the detection unit 35 stores the meaning words togetherwith the book identification information and the desired partidentification information for each of the meaning words extractedwithout repetition from the desired part analysis result data andgenerates the meaning word detection data indicating the detectionresult of the meaning words. Then, the detection unit 35 transmits themeaning word detection data to the retrieval unit 66.

At this time, the retrieval unit 66 performs the same processes as thoseperformed in the index generation process described above andtemporarily maintains the whole passage analysis result data and all ofthe text data transmitted from the acquisition unit 29.

When the retrieval unit 66 receives the word detection data from thedetection unit 35, the retrieval unit 66 retrieves all of the wordshaving the same structure as that of the detection words from the wholebook text based on the word detection data and all of the text data anddetects the identical structure word position of the identical structureword in the whole book text.

When the retrieval unit 66 receives the meaning word detection data fromthe detection unit 35, the retrieval unit 66 retrieves all of themeaning words and the identical meaning words matched with the identicalmeaning words from the whole book text based on the meaning worddetection data, the whole passage analysis result data, and all of thetext data. Then, the retrieval unit 66 detects the identical meaningword positions of the retrieved identical meaning words in the wholebook text.

Thus, the retrieval unit 66 retrieves the identical structure word fromthe whole book text based on the detection word for each of thedetection words detected without repetition from the desired part by thedetection unit 35 and detects the identical structure word position ofthe identical structure word.

The retrieval unit 66 retrieves the identical meaning word from thewhole book text based on the meaning words for each of the meaning wordsdetected without repetition from the desired part by the detection unit35 and detects the identical meaning word position of the identicalmeaning word.

At this time, the retrieval unit 66 extracts the desired partidentification information regarding the desired part and the bookidentification information from the word detection data and the meaningword detection data.

Accordingly, the retrieval unit 66 stores the identical structure wordand the identical structure word position information together with thedesired part identification information and the book identificationinformation for each of the retrieved identical structure words andgenerates identical structure word registration request data used togive a request for registering the identical structure words.

The retrieval unit 66 transmits the identical structure wordregistration request data to the registration unit 34. Moreover, theretrieval unit 66 adds retrieval completion information, which indicatesthat the retrieval of the identical structure words is completed, to theidentical structure word registration request data of the identicalstructure word finally retrieved among all of the identical structurewords retrieved from the whole book text based on one desired part.

Moreover, the retrieval unit 66 stores the identical meaning word andthe identical meaning word position information together with thedesired part identification information, the book identificationinformation, and the meaning word expressing the meaning of thecorresponding detection word for each of the retrieved identical meaningwords and generates identical meaning word registration request dataused to give a request for registering the identical meaning words.

Then, the retrieval unit 66 also transmits the identical meaning wordregistration request data to the registration unit 34. Moreover, theretrieval unit 66 adds retrieval completion information, which indicatesthat the retrieval of the identical meaning words is completed, to theidentical meaning word registration request data of the identicalmeaning word finally retrieved among all of the identical meaning wordsretrieved from the whole book text based on one desired part.

At this time, whenever the registration unit 34 receives the identicalstructure word registration request data from the retrieval unit 65, theregistration unit 34 extracts, from the identical structure wordregistration data, the book identification information, the identicalstructure word position information (the page number, the row number,the column number, and the number of characters), the identicalstructure word, and the desired part identification information.

The registration unit 34 issues identical structure word identificationinformation used to individually identify the identical structure words.At this time, even when the retrieval unit 66 retrieves the identicalstructure words which completely have the same configuration from aplurality of portions of the whole book text, the plurality of retrievedidentical structure words is different from each other in the identicalstructure word position in the whole book text.

Accordingly, the registration unit 34 issues the identical structureword identification information unique for the plurality of identicalstructure words so as to identify the plurality of identical structurewords as respective different words.

When the registration unit 34 issues the identical structure wordidentification information, the registration unit 34 stores theidentical structure word identification information together with thebook identification information, the page number, the row number, thecolumn number, the number of characters, and the identical structureword and generates the identical structure word registration data usedto register the identical structure word. Then, the registration unit 34transmits the identical structure word registration data to the storageunit 25.

Here, in the book registration database described above, a data table(hereinafter, also referred to as an identical structure wordregistration table) is generated which is used to register the identicalstructure words so as to have the same configuration as that of thedesired part registration table DT2.

The identical structure word registration table includes, as informationregistration items, an identical structure word identificationinformation registration item used to register the identical structureword identification information and a book identification informationregistration item used to register the book identification information.

The identical structure word registration table further includes, asinformation registration items, a page number registration item used toregister the page number of a page where the identical structure wordsare present and a line number registration item used to register theline number of the line where the front character of the identicalstructure word is located.

The identical structure word registration table further includes, asinformation registration items, a column number registration item usedto register the column number of a column where the front character ofthe identical structure word is located and a character numberregistration item used to register the number of characters of theidentical structure word.

The identical structure word registration table further includes, as aninformation registration item, an identical structure word registrationitem used to register the identical structure word itself as a characterstring.

Accordingly, the registration unit 34 stores the identical structureword identification information, the book identification information,the page number, the row number, the column number, the number ofcharacters, and the identical structure word stored in the identicalstructure word registration data in the information registration itemcorresponding to the identical structure word registration table byassociating the identical structure word identification information, thebook identification information, the page number, the row number, thecolumn number, the number of characters, and the identical structureword with each other.

Thus, whenever the registration unit 34 receives the request forregistering the identical structure word from the retrieval unit 66, theregistration unit 34 stores the identical structure word registrationdata indicating the identical structure word retrieved at this time inthe identical structure word registration table of the book registrationdatabase and resisters the identical structure word.

Whenever the registration unit 34 registers the identical structurewords, the registration unit 34 stores the identical structure wordidentification information and the identical structure word positioninformation of the identical structure word together with the bookidentification information and the desired part identificationinformation and generates identical structure word registrationcompletion data indicating that the registration of the identicalstructure words is completed.

The registration unit 34 transmits the identical structure wordregistration completion data to a link generation unit 75. In this case,the registration unit 34 adds retrieval completion information to theidentical structure word registration completion data of the identicalstructure word finally retrieved based on one desired part.

Whenever the registration unit 34 receives the identical meaning wordregistration request data from the retrieval unit 66, the registrationunit 34 extracts, from the identical meaning word registration data, thebook identification information, the identical meaning word positioninformation (the page number, the row number, the column number, and thenumber of characters), the identical meaning word, the desired partidentification information, and the meaning word.

The registration unit 34 issues identical meaning word identificationinformation used to individually identify the identical meaning words.At this time, even when the retrieval unit 66 retrieves the identicalmeaning words which completely have the same configuration from aplurality of portions of the whole book text, the plurality of retrievedidentical meaning words is different from each other in the identicalmeaning word position in the whole book text.

Accordingly, the registration unit 34 issues the identical meaning wordidentification information unique for the plurality of identical meaningwords so as to identify the plurality of identical meaning words asrespective different words.

When the registration unit 34 issues the identical meaning wordidentification information in this manner, the registration unit 34stores the identical meaning word identification information togetherwith the book identification information, the page number, the rownumber, the column number, the number of characters, and the identicalmeaning word and generates identical meaning word registration data usedto register the identical meaning word. Then, the registration unit 34transmits the identical meaning word registration data to the storageunit 25.

Here, in the book registration database described above, a data table(hereinafter, also referred to as an identical meaning word registrationtable) is generated which is used to register the identical meaningwords so as to have the same configuration as that of the desired partregistration table DT2.

The identical meaning word registration table includes, as informationregistration items, an identical meaning word identification informationregistration item used to register the identical meaning wordidentification information and a book identification informationregistration item used to register the book identification information.

The identical meaning word registration table further includes, asinformation registration items, a page number registration item used toregister the page number of a page where the identical meaning words arepresent and a line number registration item used to register the linenumber of the line where the front character of the identical meaningword is located.

The identical meaning word registration table further includes, asinformation registration items, a column number registration item usedto register the column number of a column where the front character ofthe identical meaning word is located and a character numberregistration item used to register the number of characters of theidentical meaning word.

The identical meaning word registration table further includes, as aninformation registration item, an identical meaning word registrationitem used to register the identical meaning word itself as a character,string.

Accordingly, the registration unit 34 stores the identical meaning wordidentification information, the book identification information, thepage number, the row number, the column number, the number ofcharacters, and the identical meaning word stored in the identicalmeaning word registration data in the information registration itemcorresponding to the identical meaning word registration table byassociating the identical meaning word identification information, thebook identification information, the page number, the row number, thecolumn number, the number of characters, and the identical meaning wordwith each other.

Thus, whenever the registration unit 34 receives the request forregistering the identical meaning word from the retrieval unit 66, theregistration unit 34 stores the identical meaning word registration dataindicating the identical meaning words retrieved at this time in theidentical meaning word registration table of the book registrationdatabase and registers the identical meaning word.

Whenever the registration unit 34 registers the identical meaning words,the registration unit 34 stores the identical meaning wordidentification information and the identical meaning word positioninformation of the identical meaning word together with the meaningwords, the book identification information, and the desired partidentification information and generates identical meaning wordregistration completion data indicating that the registration of theidentical meaning words is completed.

The registration unit 34 transmits the identical meaning wordregistration completion data to the link generation unit 75. In thiscase, the registration unit 34 adds retrieval completion information tothe identical meaning word registration completion data of the identicalmeaning word finally retrieved based on one desired part.

Whenever the desired part is instructed on the electronic book imagebeing displayed on the display unit 21, the control unit 20 allows theselection unit 28, the acquisition unit 29, the specifying unit 33, thedetection unit 35, the registration unit 34, and the retrieval unit 66to perform the same processes.

Whenever the link generation unit 75 receives the identical structureword registration completion data from the registration unit 34 duringthe index generation process, the link generation unit 75 temporarilymaintains the identical structure word registration completion data.

Moreover, whenever the link generation unit 75 receives the identicalmeaning word registration completion data from the registration unit 34during the index generation process, the link generation unit 75temporarily maintains the identical meaning word registration completiondata.

When the link generation unit 75 receives identical structure wordregistration completion data, to which the retrieval completioninformation is added, from the registration unit 34 and temporarilymaintains the identical structure word registration completion data, thelink generation unit 75 extracts the book identification information andthe desired part identification information from the identical structureword registration completion data.

Based on desired part identification information, the link generationunit 75 detects the identical structure word registration completiondata of all of the identical structure words retrieved based on onedesired part identified with the desired part identificationinformation.

Moreover, the link generation unit 75 extracts the identical structurewords from the detected identical structure word registration completiondata and compares the extracted identical structure words to each other.

As a consequence, when the identical structure words are the same (thatis, only one detection word is detected from the corresponding desiredpart), the link generation unit 75 does not classify the detectedidentical structure word registration completion data any more.

On the other hand, when the identical structure words are different(that is, two or more detection words are detected from thecorresponding desired part), the link generation unit 75 classifies thedetected identical structure word registration completion data for eachidentical structure word.

Thus, the link generation unit 75 sums up the identical structure wordregistration completion data of the identical structure words retrievedbased on one desired part for each identical structure word with theidentical structure.

The link generation unit 75 extracts the identical structure wordidentification information and the identical structure word positioninformation from the identical structure word registration completiondata of each of the identical structure words with the identicalstructure.

The link generation unit 75 generates the identical structure wordposition list in which the identical structure word position informationof the identical structure words and the identical structure wordidentification information of the identical structure words are matchedwith each other and arranged sequentially from the identical structureword position on the front side of the whole book text to the identicalstructure word position on the rear side thereof.

The link generation unit 75 adds, to the identical structure wordposition list, the book identical information of the electronic book andthe desired part identification information of the desired part used forgenerating the identical structure words.

Thus, the link generation unit 75 generates an identical structure wordlink list used to sequentially link the identical structure words toeach other in the whole hook text in accordance with the identicalstructure word list.

When two or more kinds of identical structure words are retrieved basedon one desired part, the link generation unit 75 processes therespective identical structure words in the same manner and generatesthe identical structure word link list.

When two or more desired parts are selected in the electronic book, thelink generation unit 75 also processes the desired parts and thedetection words for the identical structure words retrieved based oneach of the desired parts and generates the identical structure wordlink list.

Thus, when the link generation unit 75 generates the identical structureword link list, the link generation unit 75 transmits the identicalstructure word link list to the registration unit 34 and allows theregistration unit 34 to store the identical structure word link list inthe storage unit 25.

When the link generation unit 75 receives the identical meaning wordregistration completion data added with the retrieval completioninformation from the registration unit 34 and temporarily maintains theidentical meaning word registration completion data, the link generationunit 75 also extracts the book identification information and thedesired part identification information from the identical meaning wordregistration completion data.

Based on the desired part identification information, the linkgeneration unit 75 detects the identical meaning word registrationcompletion data of all of the identical meaning words retrieved based onone desired part identified with the desired part identificationinformation.

The link generation unit 75 extracts the meaning words from the detectedidentical meaning word registration completion data and compares theextracted meaning words to each other.

As a consequence, when the meaning words are the same (that is, only onemeaning word is detected from the corresponding desired part), the linkgeneration unit 75 does not classify the detected identical meaning wordregistration completion data any more.

On the other hand, when the meaning words are different (that is, two ormore meaning words are detected from the corresponding desired part),the link generation unit 75 classifies the detected identical meaningword registration completion data for each meaning word.

Thus, the link generation unit 75 sums up the identical meaning wordregistration completion data of the identical meaning words retrievedbased on one desired part for each meaning word (that is, the meaning ofthe identical meaning word).

The link generation unit 75 extracts the identical meaning wordidentification information and the identical meaning word positioninformation from the identical meaning word registration completion dataof each of the identical meaning words with the identical meaning.

The link generation unit 75 generates the identical meaning wordposition list in which the identical meaning word position informationof the identical meaning words and the identical meaning wordidentification information of the identical meaning words are matchedwith each other and arranged sequentially from the identical meaningword position on the front side of the whole book text to the identicalmeaning word position on the rear side thereof.

The link generation unit 75 adds, to the identical meaning word positionlist, the book identical information of the electronic book and thedesired part identification information of the desired part used forgenerating the identical meaning words.

Thus, the link generation unit 75 generates an identical meaning wordlink list used to sequentially link the identical meaning words to eachother in the whole book text in accordance with the identical meaningword list.

When two or more kinds of identical meaning words are retrieved based onone desired part, the link generation unit 75 processes the respectiveidentical meaning words in the same manner and generates the identicalmeaning word link list.

When two or more desired parts are selected in the electronic book, thelink generation unit 75 also processes the desired parts and theidentical meaning words for the identical meaning words retrieved basedon each of the desired parts and generates the identical meaning wordlink list.

Thus, when the link generation unit 75 generates the identical meaningword link list, the link generation unit 75 transmits the identicalmeaning word link list to the registration unit 34 and allows theregistration unit 34 to store the identical meaning word link list inthe storage unit 25.

In the following description, when it is not necessary to distinguishthe identical structure word link list and the identical meaning wordlink list from each other, the identical structure word link list andthe identical meaning word link list are simply referred to as inklists.

When the link generation unit 75 stores the identical structure wordlink list or the identical meaning word link list in the storage unit25, the link generation unit 75 notifies the control unit 20 of the factthat the generation of the link lists is completed.

When the control unit 20 is notified of the fact that the generation ofthe link list is completed from the link generation unit 75 during thedisplay of the electronic book image of the electronic book, the controlunit 20 stores the book identification information of the electronicbook and generates a list retrieval request data used to give a requestfor retrieving the link lists. Then, the control unit 20 transmits thelist retrieval request data to the retrieval unit 66.

When the retrieval unit 66 receives the list retrieval request data fromthe control unit 20, the retrieval unit 66 retrieves the identicalstructure word link list and the identical meaning word link list havingthe book identification information in the storage unit 25 based on thebook identification information stored in the list retrieval requestdata.

As a consequence, when the retrieval unit 66 retrieves the identicalstructure word link list and the identical meaning word link list in thestorage unit 25, the retrieval unit 66 reads the identical structureword link list and the identical meaning word link list from the storageunit 25 and transmits the identical structure word link list and theidentical meaning word link list to the control unit 20.

Here, the control unit 20 receives the identical structure word linklist and the identical meaning word link list from the retrieval unit66, the control unit 20 determines whether the identical structure wordposition information including the page number is registered in theidentical structure word link list based on the page number of theelectronic book image being displayed.

As a consequence, when the control unit 20 detects single or a pluralityof identical structure word position information including the pagenumber from the identical structure word link list, the control unit 20extracts both the detected identical structure word position informationand the corresponding identical structure word identificationinformation from the identical structure word link list.

The control unit 20 generates the emphasis display control data todisplay the corresponding identical structure words in the emphasismanner based on the identical structure word identification informationand the identical structure word identification information andtransmits the generated emphasis display control data to the displaycontrol unit 26.

Based on the page number of the electronic book image being displayed,the control unit 20 determines whether the identical meaning wordposition information including the corresponding page number isregistered in the identical meaning word link list.

As a consequence, when the control unit 20 detects the single orplurality of identical meaning word position information including thepage number is detected from the identical meaning word link list, thecontrol unit 20 extracts the detected identical meaning word positioninformation and the corresponding identical meaning word identificationinformation from the identical meaning word link list.

The control unit 20 generates the emphasis display control data used todisplay the corresponding identical meaning word in the emphasis mannerbased on the identical meaning word identification information and theidentical meaning word identification information and transmits thegenerated emphasis display control data to the display control unit 26.

When the display control unit 26 receives the emphasis display controldata from the control unit 20, the display control unit 26 processes theelectronic book image data generated for display based on the emphasisdisplay control data and transmits the processed emphasis displaycontrol data to the display unit 21.

Thus, the display control unit 26 displays the single or plurality ofidentical structure words designated based on the emphasis displaycontrol data in the emphasis manner in the electronic book image beingdisplayed on the display unit 21. Moreover, the display control unit 26also displays the single or plurality of identical meaning wordsdesignated based on the emphasis display control data in the emphasismanner in the electronic book image being displayed on the display unit21.

When the identical structure word or the identical meaning word isincluded in the text of the electronic book image being displayed on thedisplay unit 21, the control unit 20 can display the identical structureword or the identical meaning word in the emphasis manner to exhibit theidentical structure word or the identical meaning word to the user.

The control unit 20 performs the same process, when the electronic bookimage being displayed on the display unit 21 is switched in response toa flick operation of the user in this state.

Thus, when the identical structure word or the identical meaning word isalso included in the text of the electronic book image newly displayedon the display unit 21, the control unit 20 displays the identicalstructure word or the identical meaning word in the emphasis manner.

In this case, when the display control unit 26 displays the single orplurality of identical structure words in the emphasis manner in theelectronic book image being displayed on the display unit 21, thedisplay control unit 26 generates the word display region informationindicating the display region of the identical structure word with thecoordinates of the pixel position of the display surface of the displayunit 21 for each identical structure word.

Then, the display control unit 26 transmits both the word display regioninformation for each identical structure word and the identicalstructure word identification information of this identical structureword to the control unit 20.

Moreover, when the display control unit 26 displays the single orplurality of identical meaning words in the emphasis manner in theelectronic book image being displayed on the display unit 21, thedisplay control unit 26 also generates the word display regioninformation indicating the display region of the identical meaning wordwith the coordinates of the pixel position of the display surface of thedisplay unit 21 for each identical meaning word.

Then, the display control unit 26 transmits both the word display regioninformation for each identical meaning word and the identical meaningword identification information of this identical meaning word to thecontrol unit 20.

Accordingly, during the emphasis display of the identical structurewords, the control unit 20 maintains the word display region informationand the identical structure word identification information of theidentical structure words transmitted from the display control unit 26by matching the word display region information with the identicalstructure word identification information.

Moreover, during the emphasis display of the identical meaning words,the control unit 20 maintains the word display region information andthe identical meaning word identification information of the identicalmeaning words transmitted from the display control unit 26 by matchingthe word display region information with the identical meaning wordidentification information.

For example, when the control unit 20 displays the identical structurewords in the emphasis manner and the user flicks the surface of thetouch panel with the tip of his or her finger or the like to move theimage from the left side to the right side, the control unit 20 comparesthe touch position of the flick operation to the display regionindicated by the word display region information.

For example, when the control unit 20 displays the identical meaningwords in the emphasis manner and the user flicks the surface of thetouch panel with the tip of his or her finger or the like to move theimage toward the right side, the control unit 20 compares the touchposition of the flick operation to the display region indicated by theword display region information.

As a consequence, when the control unit 20 detects the flick operationthat the user executes the flick operation toward the light side of theimage at the display region of the identical structure word with the tipof his or her finger or the like, the control unit 20 determines thatthe identical structure word at the display region is instructed by theflick operation.

At this time, the control unit 20 determines that an instruction isgiven through the flick operation to display the identical structureword prior to the instructed identical structure word and closest to theinstructed identical structure word among the identical structure wordsat various identical structure word positions of the whole book text.

Then, based on the word display region information indicating thedisplay region subjected to the flick operation, the control unit 20detects the identical structure word identification information matchedwith the word display region information.

Based on the detected identical structure word identificationinformation, the control unit 20 detects the identical structure wordposition information registered immediately before the identicalstructure word position information of the instructed identicalstructure word in accordance with the identical structure word positioninformation in the identical structure word link list.

The control unit 20 extracts, from the identical structure word linklist, both the detected identical structure word position informationand the corresponding identical structure word identificationinformation. Then, the control unit 20 compares the page number includedin the identical structure word position information to the page numberof the electronic book image being displayed.

As a consequence, when the previous page of the electronic book image isexhibited during the display of the page number included in theidentical structure word position information, the control unit 20 givesan instruction to newly display the page of the electronic book image bythe page number and generates display switch control data used tocontrol display switch.

Based on the identical structure word identification information and theidentical structure word identification information, the control unit 20generates emphasis display control data used to display the instructedidentical structure word in the emphasis manner. Then, the control unit20 transmits the display switch control data and the emphasis displaycontrol data to the display control unit 26.

When the display control unit 26 receives the display switch controldata and the emphasis display control data from the control unit 20, thedisplay control unit 26 generates the electronic book image data of theinstructed page based on the display switch control data and theelectronic book data.

At this time, based on the emphasis display control data, the displaycontrol unit 26 processes the generated electronic book image data andtransmits the processed electronic book image data to the display unit21. Thus, the display control unit 26 performs switch to the electronicbook image displayed on the display unit 21, displays the electronicbook image of the instructed page, such as the instructed identicalstructure word, so as to be located in the middle of the display surfaceas near as possible, and displays the identical structure word in theemphasis manner.

When the control unit 20 switches the display of the electronic bookimage, the control unit 20 determines whether both the instructedidentical structure word and the identical structure word are includedin the text of the electronic book image newly displayed based on theidentical structure word link list.

As a consequence, when the control unit 20 determines that both theinstructed identical structure word and the identical structure word areincluded in the text of the electronic book image newly displayed, thecontrol unit 20 also displays the identical structure word other thanthe instructed identical structure word in the emphasis manner, asdescribed above.

When the control unit 20 compares the page number included in theidentical structure word position information to the page number of theelectronic book image being displayed and determines that the pagenumber indicates the page of the electronic book image being displayed,the control unit 20 does not generate the display switch control data.

Based on the identical structure word identification information, thecontrol unit 20 generates display range control data used to control thedisplay range so that the instructed identical structure word is locatedin the middle of the display surface as near as possible. Then, thecontrol unit 20 transmits the display range control data to the displaycontrol unit 26.

When the display control unit 26 receives the display range control datafrom the control unit 20, the display control unit 26 changes a portionof the electronic book image data to be transmitted to the display unit21 in accordance with the display range control data.

Thus, the display control unit 26 does not switch the electronic bookimage being displayed on the display unit 21, the display control unit26 changes the display range of the electronic book image so that theinstructed identical structure word is located in the middle of thedisplay surface as near as possible.

For example, when the flick operation is operated toward the right side,as described above, and the control unit 20 detects that the user flicksthe display region of the identical meaning word toward the right sidewith the tip of his or her finger or the like, the control unit 20determines that the identical meaning word at the display region isinstructed through the flick operation.

At this time, the control unit 20 determines that an instruction isgiven through the flick operation to display the identical meaning wordprior to the instructed identical meaning word and closest to theinstructed identical meaning word among the identical meaning words atvarious identical meaning word positions of the whole book text.

Then, based on the word display region information indicating thedisplay region subjected to the flick operation, the control unit 20detects the identical meaning word identification information matchedwith the word display region information.

Thus, the control unit 20 performs the same process as the processperformed using the identical structure word link list described aboveby using the identical meaning word link list.

Accordingly, the control unit 20 switches the electronic book imagebeing displayed into the electronic hook image of the appropriateprevious page and displays the electronic book image of the appropriateprevious page. Alternatively, the control unit 20 changes the displayrange of the electronic book image being displayed and displays theinstructed identical meaning word included in the text of the electronicbook image in the emphasis manner.

Whenever the user executes the flick operation toward the right side onthe identical structure word included in the text of the electronic bookimage being displayed, the control unit 20 can newly switches thedisplay of the electronic book image appropriately and can exhibit theidentical structure word located before the instructed identicalstructure word.

Moreover, whenever the user executes the flick operation toward theright side on the identical meaning word included in the text of theelectronic book image being displayed, the control unit 20 can newlyswitches the display of the electronic book image and can exhibit theidentical meaning word located before the instructed identical meaningword.

For example, when the control unit 20 displays the identical structurewords in the emphasis manner and the user flicks the surface of thetouch panel with the tip of his or her finger or the like to move theimage from the right side to the left side, the control unit 20 comparesthe touch position of the flick operation to the display regionindicated by the word display region information.

When the control unit 20 displays the identical meaning words in theemphasis manner and the user flicks the surface of the touch panel withthe tip of his or her finger or the like to move the image toward theleft side, the control unit 20 compares the touch position of the flickoperation to the display region indicated by the word display regioninformation.

As a consequence, when the control unit 20 detects the flick operationthat the user executes the flick operation toward the left side of theimage at the display region of the identical structure word with the tipof his or her finger or the like, the control unit 20 determines thatthe identical structure word at the display region is instructed by theflick operation.

At this time, the control unit 20 determines that an instruction isgiven through the flick operation to display the identical structureword subsequent to the instructed identical structure word and closestto the instructed identical structure word among the identical structurewords at various identical structure word positions of the whole booktext.

Then, based on the word display region information indicating thedisplay region subjected to the flick operation, the control unit 20detects the identical structure word identification information matchedwith the word display region information.

Based on the detected identical structure word identificationinformation, the control unit 20 detects the identical structure wordposition information registered immediately after the identicalstructure word position information of the instructed identicalstructure word in accordance with the identical structure word positioninformation in the identical structure word link list.

The control unit 20 extracts, from the identical structure word linklist, both the detected identical structure word position informationand the corresponding identical structure word identical information.Then, the control unit 20 compares the page number included in theidentical structure word position information to the page number of theelectronic book image being displayed.

As a consequence, when the subsequent page of the electronic book imageis exhibited during the display of the page number included in theidentical structure word position information, the control unit 20 givesan instruction to newly display the page of the electronic book image bythe page number and generates display switch control data used tocontrol display switch.

Based on the identical structure word identification information and theidentical structure word identification information, the control unit 20generates emphasis display control data used to display the instructedidentical structure word in the emphasis manner. Then, the control unit20 transmits the display switch control data and the emphasis displaycontrol data to the display control unit 26.

When the display control unit 26 receives the display switch controldata and the emphasis display control data from the control unit 20, thedisplay control unit 26 generates the electronic book image data of theinstructed page based on the display switch control data and theelectronic book data.

At this time, based on the emphasis display control data, the displaycontrol unit 26 processes the generated electronic book image data andtransmits the processed electronic book image data to the display unit21. Thus, the display control unit 26 performs switch to the electronicbook image displayed on the display unit 21, displays the electronicbook image of the instructed page, such as the instructed identicalstructure word, so as to be located in the middle of the display surfaceas near as possible, and displays the identical structure word in theemphasis manner.

When the control unit 20 switches the display of the electronic bookimage in this manner, the control unit 20 determines whether theidentical structure word as well as the instructed identical structureword is included in the text of the electronic book image newlydisplayed based on the identical structure word link list.

As a consequence, when the control unit 20 determines that theinstructed identical structure word and the identical structure word areincluded in the text of the electronic book image newly displayed, thecontrol unit 20 also displays the identical structure word other thanthe instructed identical structure word in the emphasis manner, asdescribed above.

When the control unit 20 compares the page number included in theidentical structure word position information to the page number of theelectronic book image being displayed and determines that the pagenumber indicates the page of the electronic book image being displayed,the control unit 20 does not generate the display switch control data.

Based on the identical structure word identification information, thecontrol unit 20 generates display range control data used to control thedisplay range so that the instructed identical structure word is locatedin the middle of the display surface as near as possible. Then, thecontrol unit 20 transmits the display range control data to the displaycontrol unit 26.

When the display control unit 26 receives the display range control datafrom the control unit 20, the display control unit 26 changes a portionof the electronic book image data to be transmitted to the display unit21 in accordance with the display range control data.

Thus, the display control unit 26 does not switch the electronic bookimage being displayed on the display unit 21, the display control unit26 changes the display range of the electronic book image so that theinstructed identical structure word is located in the middle of thedisplay surface as near as possible.

For example, when the flick operation is operated toward the left side,as described above, and the control unit 20 detects that the user flicksthe display region of the identical meaning word toward the left sidewith the tip of his or her finger or the like, the control unit 20determines that the identical meaning word at the display region isinstructed through the flick operation.

At this time, the control unit 20 determines that an instruction isgiven through the flick operation to display the identical meaning wordprior to the instructed identical meaning word and closest to theinstructed identical meaning word among the identical meaning words atvarious identical meaning word positions of the whole book text.

Then, based on the word display region information indicating thedisplay region subjected to the flick operation, the control unit 20detects the identical meaning word identification information matchedwith the word display region information.

Thus, the control unit 20 performs the same process as the processperformed using the identical structure word link list described aboveby using the identical meaning word link list.

Accordingly, the control unit 20 newly switches the electronic bookimage being displayed into the electronic book image of the appropriatesubsequent page and displays the electronic book image of theappropriate previous page. Alternatively, the control unit 20 changesthe display range of the electronic book image being displayed anddisplays the instructed identical meaning word included in the text ofthe electronic book image in the emphasis manner.

Whenever the user executes the flick operation toward the left side onthe identical structure word included in the text of the electronic bookimage being displayed, the control unit 20 can appropriately switch thedisplay of the electronic book image and can exhibit the identicalstructure word located after the instructed identical structure word.

Moreover, when the user executes the flick operation toward the leftside on the identical meaning word included in the text of theelectronic book image being displayed, the control unit 20 canappropriately switches the display of the electronic book image and canexhibit the identical meaning word located after the instructedidentical meaning word.

Accordingly, when the control unit 20 generates the link for theelectronic book, the control unit 20 can permit easily searching for theassociation portion such as a phrase or a clause associated with thedesired part by utilizing the link function.

Even when the control unit 20 displays the identical structure word orthe identical meaning word in the emphasis manner based on the linklist, the control unit 20 displays the identical structure word and theidentical meaning word in mutually different display states in theemphasis manner, as in the index described above.

Thus, the control unit 20 can give a notification of the fact that thedegree of the relevance with the association portion including thedesired part and the identical structure word is different from thedegree of the relevance with the association portion including thedesired part and the identical meaning word.

Even when the control unit 20 executes the link generation process, asin the case where the desired part is selected without performing thelink generation process, the control unit 20 detects the keyword inresponse to the selection of the desired part, generates the tag,registers the desired part, and retrieves the association information.

Accordingly, when the desired part is selected in the text of theelectronic book image even in a case where the electronic book image ofthe electronic book in which the link is generated is displayed, asdescribed above, the control unit 20 displays the desired part in theemphasis manner.

The control unit 20 displays the identical structure word and theidentical meaning word in the emphasis manner in the mutually differentdisplay states, as described above, and also displays the identicalstructure word and the identical meaning word in the emphasis manner ina display state different from the display states of the desired part.

Accordingly, when the control unit 20 displays the identical structureword or the identical meaning word of the desired part included in thedesired part in the text of the electronic book image being displayed onthe display unit 21 in the emphasis manner, the control unit 20 caneasily exhibit the identical structure word or the identical meaningword in the desired part so that the user can recognize the identicalstructure word or the identical meaning word.

When the control unit 20 displays the electronic book image of theelectronic book in which the link is generated, and for example, theuser reads the desired part, the control unit 20 can easily cope with arequest for reading the association portion associated with the desiredpart in the electronic book.

When the control unit 20 displays the identical structure word in theemphasis manner in the electronic book image being displayed, thecontrol unit 20 can allow the user to execute a predetermined operationof instructing the identical structure word and can allow the user todelete the identical structure word from the identical structure wordlink list.

In effect, when the control unit 20 receives the instruction to deletethe identical structure word in the electronic book image beingdisplayed from the identical structure word link list by a predeterminedoperation of the user, the control unit 20 stops displaying theinstructed identical structure word in the emphasis manner.

The control unit 20 detects and deletes the identical structure wordposition information and the identical structure word identificationinformation of the instructed identical structure word in the identicalstructure word link list. Thus, the control unit 20 invalidates thesearch for the identical structure word instructed by the user and thenmay not display the identical structure word in the emphasis manner.

Even when the control unit 20 displays the identical meaning word in theemphasis manner in the electronic book image being displayed, thecontrol unit 20 can allow the user to execute a predetermined operationof instructing the identical meaning word and can allow the user todelete the identical meaning word from the identical meaning word linklist.

Moreover, when the control unit 20 receives the instruction to deletethe identical meaning word in the electronic book image being displayedfrom the identical meaning word link list by a predetermined operationof the user, the control unit 20 stops displaying the instructedidentical meaning word in the emphasis manner.

The control unit 20 detects and deletes the identical meaning wordposition information and the identical meaning word identificationinformation of the instructed identical meaning word in the identicalmeaning word link list. Thus, the control unit 20 invalidates the searchfor the identical meaning word instructed by the user and then may notdisplay the identical meaning word in the emphasis manner.

Accordingly, the control unit 20 can prevent the identical structureword or the identical meaning word, which is included in the associationportion determined not to be associated with the desired part in theelectronic book image for the user, from being unnecessarily displayedin the emphasis manner to search for the association portion.

The control unit 20 can prevent a situation where it is difficult forthe user to read the text itself due to the numerous identical structurewords or the identical meaning words displayed in the emphasis manner inthe electronic book image.

When the control unit 20 displays the electronic book image of theelectronic book in which the link list is generated and displays thedesired part selected in the generation of the link list in the emphasismanner, the control unit 20 can allow the user to execute apredetermined operation of instructing the desired part and cancel theselection.

In effect, when the control unit 20 receives the instruction ofcancelling the selection of the desired part in the electronic bookimage being displayed by the predetermined operation of the user, thecontrol unit 20 stops displaying the desired part in the emphasismanner.

At this time, the control unit 20 stores the desired part identificationinformation of the instructed desired part and transmits deletionrequest data used to give a request for deleting the registration of thedesired part to the registration unit 34.

Accordingly, at this time, the registration unit 34 extracts the desiredpart identification information from the deletion request datatransmitted from the control unit 20. Then, based on the desired partidentification information, the registration unit 34 detects and deletesthe desired part registration data corresponding to the desired partidentification information in the desired part registration table DT2 inthe storage unit 25.

Thus, the control unit 20 cancels the selection of the desired partinstructed by the user in order not to subsequently display the desiredpart in the emphasis manner.

At this time, based on the desired part identification informationextracted from the deletion request data, the registration unit 34detects and deletes the identical structure word link list and theidentical meaning word link list including the desired partidentification information in the storage unit 25.

The control unit 20 thus invalidates the retrieval of the identicalstructure word and the identical meaning word searched based on thedesired part instructed by the user in order not to subsequently displaythe identical structure word and the identical meaning word in theemphasis manner.

Accordingly, when the control unit 20 determines that it is notnecessary to select the desired part selected once by the user in theelectronic book image, the control unit 20 cancel the selection in ordernot to subsequently display the desired part in the emphasis mannerunnecessarily.

When it is not necessary to search for the association portionassociated with the desired part in response to the cancellation of theselection of the desired part, the control unit 20 can prevent theidentical structure word and the identical meaning word sued to searchfor the association portion associated with the desired part from beingunnecessarily displayed in the emphasis manner.

2-2-4. Classification Process

Next, a classification process of classifying the desired parts selectedin various electronic books will be described. First, the desired partselected in the electronic book by the user can be said to be a partwhich the user is particularly interested in the whole book text of theelectronic book.

Accordingly, the control unit 20 does not classify the desired parts inaccordance with genre, for example, but classifies the desired parts inaccordance with an interest of the user. Therefore, the classifiedelectronic books can easily be used subsequently in the search of thedesired part.

Since the control unit 20 realizes the classification of the desiredparts, the meanings of the keywords detected from the desired parts areused. Moreover, the control unit 20 hierarchically classifies thedesired parts to easily use the classification result when the desiredparts are subsequently searched.

In effect, when the user executes a predetermined operation to give arequest for classifying the desired parts, the control unit 20 performsthe classification process in response to the predetermined operation incooperation with each circuit unit. At this time, for example, thecontrol unit 20 allows the user to arbitrarily select the folder name ofsingle or a plurality of first hierarchical holders which is the highestfolder among hierarchical folders used to hierarchically classify thedesired parts.

At this time, for example, the control unit 20 allows the display unit21 to exemplify the hierarchical meanings (for example, the meanings ofa word “COOKING POT” and higher hierarchical concept words “COOKING” and“FOOD”) of the superordinate concept for a predetermined word includedin the desired part.

Thus, the control unit 20 allows the user having already read theelectronic book to select one or more words such as “COOKING” or“HISTORY, HISTORICAL FIGURES” expressing the meaning of thesuperordinate concept considered to be suitable to classify the desiredpart as the folder name of the first hierarchical folder.

Thus, when the user select the folder name of the single or plurality offirst hierarchical folders, the control unit 20 generates folder namedata indicating the selected folder names for each first hierarchicalfolder and transmits the folder name data to a classification unit 77.

When an electronic book is instructed for acquisition by the user, thewhole book text can be said to be the desired part. In particular, sincean electronic book acquired by cutting out a text of a home page, areport, or the like as a scrap is a part which the user is interested inand gives an instruction to cut from the text of the home page, thereport, or the like, the electronic book can be said to be a desiredpart itself.

Therefore, the selection unit 28 determines whether there is anunregistered electronic book in the book registration table DT1 in thestorage unit 25 under the control of the control unit 20 based on theelectronic book data stored in the storage unit 25 and the bookregistration data in the book registration table DT1.

That is, the selection unit 28 determines whether there is an electronicbook in which a part of the text has not been selected once as thedesired part after the acquisition in the storage unit 25.

As a consequence, when there is the unregistered electronic book in thebook registration table DT1, the selection unit 28 selects all of thetext data of the electronic book as an analysis target. Then, theselection unit 28 reads the book attribute data and all of the text dataof the unregistered electronic book from the storage unit 25 andtransmits the book attribute data and all of the text data to theacquisition unit 29.

When the acquisition unit 29 receives the book attribute data and all ofthe text data from the selection unit 28, the acquisition unit 29temporarily maintains the book attribute data and transmits all of thetext data to the natural language processing block 30 to give a requestfor natural language processing.

At this time, the natural language processing block 30 analyzes themorpheme and syntax of the whole book text based on all of the textdata, as described above, and returns the whole passage analysis resultdata obtained as the analysis result and all of the text data to theacquisition unit 29.

When the acquisition unit 29 receives the whole passage analysis resultdata and all of the text data from the natural language processing block30, the acquisition unit 29 transmits the whole passage analysis resultdata and all of the text data together with the temporarily maintainedbook attribute data to the detection unit 35.

When the detection unit 35 receives the whole passage analysis resultdata and all of the text data together with the book attribute data fromthe acquisition unit 29, the detection unit 35 detects the keywords fromthe whole book text, which is based on all of the text data, based onthe whole analysis result data, as in the case where the detection unit35 detects the keywords from the desired part.

Moreover, the detection unit 35 also detects the meanings of thedetected keywords based on the whole passage analysis result data. Then,the detection unit 35 extracts the page number of the page, in which thekeywords are detected, for each of the detected keywords from all of thetext data.

Moreover, the detection unit 35 extracts the keywords (that is, thecharacter codes of the plurality of characters expressing the keywords)and the character position information (of the plurality of charactersexpressing the keywords) corresponding to the keywords for each of thedetected keywords from all of the text data.

The detection unit 35 sets the score of the keywords to 1 for eachkeyword. Moreover, the detection unit 35 extracts the meaning wordsexpressing the meanings of the keywords from all of the text data foreach keyword.

Thus, the detection unit 35 stores the page numbers, the keywords, thecharacter position information, the meaning words, and the scores foreach keyword and generates keyword data indicating the keywords. Then,the detection unit 35 transmits both the keyword data and the bookattribute data to the registration unit 34.

At this time, when the registration unit 34 receives the keyword dataand the book attribute data from the detection unit 35, as describedabove, the registration unit 34 generates book registration data basedon the book attribute data and registers the electronic book in whichthe keywords are detected in the book registration table DT1.

The registration unit 34 issues the keyword identification information,as in the case where the registration unit 34 registers the desired partdescribed above, and generates the keyword registration data having thesame configuration as that of the desired part registration data basedon the keyword identification information, the keyword data, and thebook attribute data.

Thus, the registration unit 34 transmits the keyword registration datato the storage unit 25 and registers the keywords in the desired partregistration table DT2 as in the desired part.

At this time, the registration unit 34 generates the keywordregistration data having the above-described configuration based on thekeyword identification information and the keyword data again using thekeyword identification information. Then, the registration unit 34transmits the keyword registration data to the storage unit 25 andregisters the keywords in the keyword registration table DT3.

Moreover, since the registration unit 34 uses the same keywordidentification information in the registration of the keywords in thedesired part registration table DT2 and in the registration of thekeywords in the keyword registration table DT3, the association unit 60does not perform the association process.

Thus, the control unit 20 automatically specifies the keywords importantto the understanding of the contents of an electronic book, in which thedesired part is not selected, from the whole book text of the electronicbook. The control unit 20 considers the keywords as the desired part andclassifies the keywords together with the desired part selected by theuser.

The association comment input as the association information of thedesired part is described to show the item that the user is interestedin for the desired part. Therefore, although the association comment isnot the electronic book, the association comment can be said to be thedesired part indicating the interest of the user.

Accordingly, the selection unit 28 also determines whether theassociation comment input as the association information of the desiredpart by the user is stored in the storage unit 25 under the control ofthe control unit 20. As a consequence, when the selection unit 28determines that the association comment is stored in the storage unit25, the selection unit 28 selects the association comment to beanalyzed.

Then, the selection unit 28 reads the association comment and the tagidentification information associated with the association comment fromthe storage unit 25, adds the tag identification information to the readassociation comment, and transmits the association comment to theacquisition unit 29.

When the acquisition unit 29 receives the association comment from theselection unit 28, the acquisition unit 29 transmits the associationcomment to the natural language processing block 30 to give a requestfor natural language processing.

As a consequence, when the natural language processing block 30 analyzesthe association comment, as in the instruction estimated part data orall of the text data described above, and the acquisition unit 29receives the association comment and the comment analysis result datafrom the natural language processing block 30, the acquisition unit 29transmits the association comment and the comment analysis result datato the detection unit 35.

When the detection unit 35 receives the association comment and thecomment analysis result data from the acquisition unit 29, as describedabove, the detection unit 35 detects the keywords from the associationcomment based on the comment analysis result data and detects themeanings of the detected keywords without overlap. Then, the detectionunit 35 transmits both the detected meaning words of the keywords andthe tag identification information added to the association comment tothe classification unit 77.

Thus, the selection unit 28 also considers the association commentstored in the storage unit 25 as the desired part and the associationcomment is processed as the desired part and can be classified togetherwith the desired, part selected by the user.

Hereinafter, a process of classifying the desired part by theclassification unit 77 will be described. Hereinafter, a case will bedescribed in which the keywords and the association comment prepared asthe classification target, as described above, are classified togetherwith the desired part selected by the user.

When the classification unit 77 receives the single or plurality offolder name data from the control unit 20, the classification unit 77generates the first hierarchical folder to which the folder nameindicated by the folder name data is added for each folder name data.

Based on the folder names of any one of the first hierarchical folders,the classification unit 77 searches for the meaning words including thewords identical to the folder name or the meaning words including theword similar to the folder name in the keyword registration table DT3 ofthe storage unit 25 in disregard of the overlap in accordance with afuzzy retrieval method.

As a consequence, when the classification unit 77 searches for themeaning word corresponding to the folder name in the keywordregistration table DT3, the classification unit 77 reads the meaningword retrieved from the storage unit 25 and reads the keywordidentification information corresponding to the retrieved meaning word.

Based on the keyword identification information read from the storageunit 25, the classification unit 77 searches for the desired partidentification information corresponding to the keyword identificationinformation in the keyword association table DT5 of the storage unit 25.

As a consequence, when the classification unit 77 searches for thedesired part identification information associated with the keywordidentification information in the keyword association table DT5 of thestorage unit 25, the classification unit 77 reads the retrieved desiredpart identification information from the storage unit 25.

That is, the classification unit 77 reads, from the storage unit 25, theretrieved desired part identification information as informationindicating the desired part classified to the first hierarchical folderof the folder name used in the retrieval.

The classification unit 77 determines whether there is the keywordidentification information (that is, the keyword identificationinformation of the keyword registered in the desired part registrationtable DT2) with which the desired part identification information maynot be searched in the keyword association table DT5 of the storage unit25.

As a consequence, when the classification unit 77 determines that thereis the keyword identification information with which the desired partidentification information may not be searched in the keywordassociation table DT5, the classification unit 77 detects the keywordidentification information as information indicating the keywordclassified to the first hierarchical folder of the folder name used inthe retrieval.

Moreover, based on the folder name, the classification unit 77 searchesfor the meaning word including the word identical to the folder name orthe meaning words including the word similar to the folder name amongthe meanings, to which the tag identification information is added, indisregard of the overlap in accordance with the fuzzy retrieval method.

As a consequence, when the classification unit 77 searches for themeaning word corresponding to the folder name among the meaning words towhich the tag identification information is added, the classificationunit detects the tag identification information added to the meaningwords without overlap.

The classification unit 77 detects the detected tag identificationinformation as information indicating the association comment classifiedto the first hierarchical folder of the folder name used in theretrieval.

Here, the classification unit 77 sums up the number of retrieved desiredpart identification information, the number of detected keywordidentification information, and the number of detected tagidentification information and calculates the classification number ofdesired parts, keywords, and association comments to the firsthierarchical folder.

The classification unit 77 determines whether the classification numberis equal to greater than a predetermined number set in advance. As aconsequence, when the summed classification number is less than thepredetermined number, the classification unit 77 generates one secondhierarchical folder lower by one layer than the first hierarchicalfolder in association with the first hierarchical folder.

Based on the retrieved desired part identification information, theclassification unit 77 retrieves and reads the desired part registrationdata including the desired part identification information in thedesired part registration table DT2 from the storage unit 25.

Moreover, based on the detected keyword identification information, theclassification unit 77 retrieves and reads the keyword registration dataincluding the keyword identification information in the desired partregistration table DT2 from the storage unit 25.

The classification unit 77 stores all of the retrieved desired partregistration data in the second hierarchical folder. Moreover, theclassification unit 77 also stores all of the retrieved keywordregistration data in the second hierarchical folder.

The classification unit 77 stores the detected tag identificationinformation in the second hierarchical folder and also storesclassification number information indicating the obtained classificationnumber.

Thus, the classification unit 77 completes the classification of thedesired parts, the keywords, and the association comments to the firsthierarchical folder of the folder name used in the retrieval.

On the other hand, when the classification number is equal to or greaterthan the predetermined number, the classification unit 77 separates thewords expressing one meaning from the respective meanings retrieved withthe folder name without overlap.

The classification unit 77 generates the second hierarchical folders ofthe same number as the number of the words (words separated from themeaning words without overlap) in the folder lower than the firsthierarchical folder by one layer in association with the firsthierarchical folder. Moreover, the classification unit 77 adds the wordsseparated without overlap from the meaning words as folder names to thesecond hierarchical folder.

For example, as for the folders for classifying the desired parts or thelike, the user selects and sets the degree that the lower hierarchicalfolders are generated from the first hierarchical folder.

For example, when the folders are set to be generated up to the thirdhierarchical folder lower than the second hierarchical folder by onelayer, the classification unit 77 searches for the meaning words basedon the folder name of any one of the second hierarchical folders, as inthe first hierarchical folder described above.

As a consequence, when the classification unit 77 searches for themeaning word corresponding to the folder name in the keywordregistration table DT3, the classification unit 77 reads the meaningword retrieved from the storage unit 25 and reads the keywordidentification information corresponding to this meaning word.

The classification unit 77 searches for the desired part identificationinformation in the keyword association table DT5 based on the keywordidentification information read from the storage unit 25. As aconsequence, when the classification unit 77 searches for the desiredpart identification information associated with the keywordidentification information, the classification unit 77 reads theretrieved desired part identification information from the storage unit25.

When there is the keyword identification information for which thedesired part identification information may not be retrieved, theclassification unit 77 detects this keyword identification informationas information indicating the keyword classified to the secondhierarchical folder.

When the classification unit 77 retrieves the meaning word correspondingto the folder name among the meaning words to which the tagidentification information is added, the classification unit 77 detectsthe tag identification information added to this retrieved meaning wordas information indicating the association comment classified to thesecond hierarchical folder without overlap.

The classification unit 77 detects the desired part, the keyword, andthe association comment classified to the second hierarchical folder ofthe folder name used in the retrieval based on the search result of themeaning word, as described above.

Moreover, the classification unit 77 sums up the number of retrieveddesired part identification information, the number of detected keywordidentification information, and the number of detected tagidentification information and calculates the classification number ofdesired parts, keywords, and association comments to the secondhierarchical folders.

In this case, the classification unit 77 generates one thirdhierarchical folder lower than the second hierarchical folder by onelayer in association with the second hierarchical folder withoutcomparing the summed classification number to a predetermined number.

Based on the detected desired part identification information, theclassification unit 77 retrieves and reads the desired part registrationdata including the desired part identification information in thedesired part registration table DT2 from the storage unit 25.

Moreover, based on the detected keyword identification information, theclassification unit 77 retrieves and reads the keyword registration dataincluding the keyword identification information in the desired partregistration table DT2 from the storage unit 25.

The classification unit 77 stores all of the retrieved desired partregistration data in the third hierarchical folder and also stores allof the retrieved keyword registration data in the third hierarchicalfolder.

The classification unit 77 stores the detected tag identificationinformation in the third hierarchical folder and also storesclassification number information indicating the obtained classificationnumber.

Thus, the classification unit 77 completes the classification of thedesired parts, the keywords, and the association comments to the secondhierarchical folder of the folder name used in the retrieval.

Moreover, the classification unit 77 classifies the desired parts, thekeywords, and the association comments to the second hierarchicalfolders by performing the same process on the remaining secondhierarchical folders.

When the classification unit 77 completes the above-described series ofprocesses on one first hierarchical folder, the classification unit 77performs the above-described processes on the remaining firsthierarchical folders to classify the desired parts, the keywords, andthe association comments.

Thus, the classification unit 77 classifies the desired parts, thekeywords, and the association comments based on the meanings of thecorresponding keywords. Therefore, for example, when the classificationunit 77 detects only one keyword from the desired part, theclassification unit 77 classifies the desired part to any one of thefirst hierarchical folders.

On the other hand, for example, when the classification unit 77 detectsthe plurality of keywords from the desired part, the classification unit77 classifies the desired part to the plurality of first hierarchicalfolders in an overlap manner based on the meanings of these keywords.

That is, as shown in FIG. 31, the classification unit 77 can classifythe desired part so as to sum up the items associated with the contentsirrespective of the kinds of selected electronic book.

The classification unit 77 can classify the keywords detected like thedesired parts based on the meanings of the keywords from the electronicbook so as to sum up the items identical or similar to the meaningirrespective of the electronic book.

The classification unit 77 can also classify the association commentsadded to the desired part so as to sum up the items associated with thecontents irrespective of the electronic book, as in the desired part.

When the classification unit 77 classifies the desired parts, thekeywords, and the association comments in this manner, theclassification unit 77 determines whether the third hierarchical foldersare associated with the second hierarchical folder automaticallygenerated for the classification of the desired parts, the keywords, andthe association comments.

As a consequence, when one third hierarchical folder is associated withthe second hierarchical folders, the classification unit 77 stores theclassification number information stored in the third hierarchicalfolder even in the second hierarchical folders.

Moreover, when two or more third hierarchical folders are associatedwith the second hierarchical folders, the classification unit 77 sums upthe classification number indicated by the classification numberinformation stored in the third hierarchical folders and stores theclassification number information indicating the summed classificationnumber in the second hierarchical folders.

When the classification number information is completely stored in thesecond hierarchical folders, the classification unit 77 continuesdetecting the classification number of the second hierarchical foldersassociated with the first hierarchical folders.

As a consequence, when one second hierarchical folder is associated withthe first hierarchical folders, the classification unit 77 stores theclassification number information stored in the second hierarchicalfolder even in the first hierarchical folders.

Moreover, when two or more second hierarchical folders are associatedwith the first hierarchical folders, the classification unit 77 sums upthe classification number indicated by the classification numberinformation stored in the second hierarchical folders and stores theclassification number information indicating the summed classificationnumber in the first hierarchical folders.

Thus, the classification unit 77 can detect the classification number ofdesired parts, keywords, and association comments respectivelyclassified to the first to third hierarchical folders.

When the classification unit 77 appropriately generates the first tothird hierarchical folders and classifies the desired parts, thekeywords, and the association comments, the classification unit 77stores the generated first to third hierarchical folders in the storageunit 25. Thus, the classification unit 77 ends all of the classificationof the desired parts, the keywords, and the association comments andnotifies the control unit 20 of the fact that the classification ends.

When the control unit 20 is notified of the fact that the classificationof the desired parts, the keywords, and the association comments endsfrom the classification unit 77, for example, the control unit 20 allowsthe display unit 21 to notify the user of the fact that theclassification ends and the fact that the result of the classificationis subsequently used in the retrieval of the desired parts, thekeywords, and the association comments.

Moreover, the control unit 20 performs the classification processdescribed above, whenever the user gives a request. Thus, the controlunit 20 can reclassify the desired parts, the keywords, and theassociation comments, for example, by newly adding or deleting the firsthierarchical folder and automatically adding the second and thirdhierarchical folders appropriately.

When the user executes a predetermined operation to give a request fordisplaying the classification result of the desired parts, the keywords,and the association comments, the control unit 20 reads all of the firstto third hierarchical folders from the storage unit 25 in response tothe request.

In the following description, when it is not necessary to distinguishthe desired parts, the keywords, and the association comments from eachother, the desired parts, the keywords, and the association comments aresimply referred to as classification information.

The control unit 20 generates introduction classification result data bytracing the classification result of the classification informationsequentially from the higher hierarchy classification result to thelower hierarchy classification result based on the first to thirdhierarchical folders.

In effect, the control unit 20 extracts the classification numberinformation from each first hierarchical folder. Moreover, based on theclassification number information, the control unit 20 calculates aratio of the classification number of classification informationregarding each first hierarchical folder to the classification number(the total number including the kinds of overlapping classificationinformation) regarding classification information of all the firsthierarchical folders.

Based on the calculation result, the control unit 20 generates firsthierarchy classification result data indicating a ratio of theclassification number of classification information to each firsthierarchical folder using, for example, a circular graph as the firsthierarchy classification result of the classification information. Thecontrol unit 20 transmits the first hierarchy classification result datato the display control unit 26.

At this time, the display control unit 26 transmits the first hierarchyclassification result data transmitted from the control unit 20 to thedisplay unit 21. Thus, the display control unit 26 displays a firsthierarchy classification result image 80 shown in FIG. 32 on the displayunit 21 based on the first hierarchy classification result data.

The first hierarchy classification result image 80 shows the circulargraph indicating a ratio of the classification number of classificationinformation regarding each first hierarchical folder to theclassification number of classification information regarding all thefirst hierarchical folders. The first hierarchy classification resultimage 80 also shows the folder names of the first hierarchical foldersby matching the folder names with the individual regions of the circulargraph.

Thus, the control unit 20 can introduce the classification result of theclassification information regarding the individual first hierarchicalfolders using the first hierarchy classification result image 80.

In the first hierarchy classification result image 80, the control unit20 expresses the classification result of each first hierarchicalfolder, to which the folder names expressing the meaning of thesuperordinate concept are added, not using the specific classificationnumber but using the ratio to the classification number of theclassification information of all the first hierarchical folders.

Therefore, the control unit 20 can show the first hierarchyclassification result image 80 so that the user can easily recognize andconfirm which items the user is interested in and how much the user isinterested in.

In this state, for example, when the user instructs one of the firsthierarchical folders as a separation region of the circular graph withthe first hierarchy classification result image 80, the control unit 20detects all of the second hierarchical folders associated with theinstructed first hierarchical folder.

As a consequence, when the control unit 20 can associate the pluralityof second hierarchical folders with the instructed first hierarchicalfolder, the control unit 20 extracts the classification numberinformation from each of the second hierarchical folders.

Moreover, based on the classification number information, as in thefirst hierarchical folders, the control unit 20 calculates a ratio ofthe classification number of classification information regarding eachsecond hierarchical folder to the classification number (the totalnumber including the kinds of overlapping classification information) ofclassification information regarding all the second hierarchicalfolders.

Based on the calculation result, the control unit 20 generates secondhierarchy classification result data indicating a ratio of theclassification number of classification information to each secondhierarchical folder using, for example, the circular, graph as thesecond hierarchy classification result of the classificationinformation. The control unit 20 transmits the second hierarchyclassification result data to the display control unit 26.

Thus, the control unit 20 allows the display control unit 26 to show asecond hierarchy classification result image (not shown) with the sameconfiguration of that of the first hierarchy classification result image80 on the display unit 21 and can introduce the classification result ofthe classification information regarding the individual secondhierarchical folders.

Therefore, the control unit 20 can show the second hierarchyclassification result image so that the user can further easilyrecognize and confirm which items the user is interested in and how muchthe user is interested in.

At this time, the control unit 20 can permit the user to instruct one ofthe second hierarchical folders as the separation region of the circulargraph with the second hierarchy classification result image.

The control unit 20 extracts data regarding the classification numberinformation when the control unit 20 can associate only one of the firsthierarchical folders (or the second hierarchical folders) with thesecond hierarchical folder (or the third hierarchical folder) instructedby the user.

That is, when the layer lower than the first hierarchical folder (or thesecond hierarchical folder) instructed by the user by one layer is thelowest hierarchical layer, the control unit 20 extracts the desired partregistration data or the keyword registration data, or the like from thesecond hierarchical folder (or the third hierarchical folder) to thelowest hierarchical layer.

Based on the desired part registration data or the keyword registrationdata, or the like, the control unit 20 generates classificationinformation selection image data used to select the classificationinformation (the desired parts, the keywords, and the associationcomments) classified to the second hierarchical folders (or the thirdhierarchical folders) in the lowest hierarchical layer. Then, thecontrol unit 20 transmits the classification information selection imagedata to the display control unit 26.

At this time, the display control unit 26 transmits the classificationinformation selection image data transmitted from the control unit 20 tothe display unit 21 and displays a classification information selectionimage (not shown) having nearly the same configuration as that of thethird hierarchical index image described above with reference to FIG. 30on the display unit 21.

The classification information selection image shows the book title ofthe electronic book including the desired parts or the keywordsclassified to the corresponding second hierarchical folders (or thethird hierarchical folders).

The classification information selection image shows the page numberindicating the position of the desired parts or the keywords in thewhole book text classified to the corresponding second hierarchicalfolders (or the third hierarchical folders) or the row number, thecolumn number, and the like of the front character.

The classification information selection image shows a character stringline such as “Comment 1” or “Comment 2” indicating that the associationcomments are classified, when the association comments are classified tothe corresponding second hierarchical folders (or the third hierarchicalfolders).

When one of the desired parts is instructed as information regarding thecorresponding book title or the like on the classification informationselection image, the control unit 20 reads the electronic book dataincluding the instructed desired part from the storage unit 25 based onthe desired part registration data corresponding to the instructeddesired part.

Then, the control unit 20 transmits both the desired part registrationdata and the electronic book data to the display control unit 26. Thus,the display control unit 26 displays the electronic book image of thepage including the instructed desired part based on the desired partregistration data and the electronic book data on the display unit 21and displays the desired part in the emphasis manner.

When one of the keywords is instructed as information regarding thecorresponding book title or the like on the classification informationselection image, the control unit 20 reads the electronic book dataincluding the instructed keyword from the storage unit 25 based on thekeyword registration data corresponding to the instructed keyword.

Then, the control unit 20 transmits both the keyword registration dataand the electronic book data to the display control unit 26. Thus, thedisplay control unit 26 displays the electronic book image of the pageincluding the instructed keyword based on the keyword registration dataand the electronic book data on the display unit 21 and displays thekeyword in the emphasis manner.

When one of the association comments is instructed as the correspondingcharacter string such as “Comment 1” on the classification informationselection image, the control unit 20 generates comment retrieval requestdata storing the tag identification information corresponding to theinstructed association comment and transmits the comment retrievalrequest data to the retrieval unit 66.

As a consequence, when the retrieval unit 66 retrieves and transmits theinstructed association comment, the control unit 20 transmits theassociation comment to the display control unit 26. Then, the displaycontrol unit 26 displays the association comment on the display unit 21.

Thus, the control unit 20 introduces the classification result of theclassification information and also retrieves and displays theclassification information using the classification result. Accordingly,the control unit 20 can introduce the classification information to theuser.

2-2-5. Introduction Sharing Process

Next, an instruction sharing process will be described in which thecontrol unit 20 receives an instruction of another user with apreference similar to that of a user using the information sharingapparatus 14.

For example, the control unit 20 performs user registration to theinformation sharing apparatus 14 in advance to share various kinds ofinformation regarding an electronic book with the information displayterminals 11 and 12 of other users using the information sharingapparatus 14.

For example, when the user gives a request for displaying the electronicbook and gives a request for supplying the book association data to theinformation sharing apparatus 14 whenever selecting the desired part,the control unit 20 asks the retrieval unit 66 to retrieve the bookassociation data whenever the selection of the desired part ends.

That is, when the selection of one desired part instructed in the textof the electronic book image ends, the control unit 20 asks theretrieval unit 66 to retrieve the electronic book used to select thedesired part or the book, association data regarding the desired part.

Here, the book association data is information including the bookregistration data, the desired part registration data, the keywordregistration data, the tag registration data, and the associationcomment generated in response to the selection of the desired part.

When the retrieval unit 66 retrieves the book association data of theelectronic book and the control unit 20 receives the book associationdata, the control unit 20 transmits both the book association data ofthe electronic book and user registration information used in the userregistration to the transmission unit 23. Thus, the transmission unit 23transmits the book association data and the user registrationinformation transmitted from the control unit 20 to the informationsharing apparatus 14 via the network 13.

Whenever the information sharing apparatus 14 receives the bookassociation data and the user registration information transmitted fromthe plurality of information display terminals 11 and 12, as shown inFIG. 33, the information sharing apparatus 14 accumulates the bookassociation data and the user registration information in associationwith the book association data and the user registration information.

When the control unit 20 receives a request for receiving an instructionof another user with a reference similar to that of the user from theinformation sharing apparatus 14 by a predetermined operation of theuser, the control unit 20 stores registration information used in theuser registration, generates instruction request data used to give arequest for the instruction of another user, and transmits theinstruction request data to the transmission unit 23. Thus, thetransmission unit 23 transmits the instruction request data transmittedfrom the control unit 20 to the information sharing apparatus 14 via thenetwork 13.

When the information sharing apparatus 14 receives the instructionrequest data transmitted from the information display terminal 11, theinformation sharing apparatus 14 extracts the user registrationinformation from the received instruction request data and specifies thehook association data associated with the user registration information.

The information sharing apparatus 14 performs a cooperation filteringprocess using the specified book association data and the plurality ofother book association data accumulated at this time.

Thus, the information sharing apparatus 14 specifies other users thatacquire the electronic book and is the same as the user (hereinafter,also referred to as an instruction request user) giving the instructionrequest.

The information sharing apparatus 14 narrows, from the specified otherusers, other users that shows an interest in the same items or similaritems with the instruction request user (that is, has a similarpreference) and acquires the electronic book different from that of theinstruction request user.

The information sharing apparatus 14 generates user instruction dataindicating the narrowed other users and returns the generated userinstruction data to the information display terminal 11 of theinstruction request user via the network 13.

At this time, the reception unit 24 of the user display terminal 11 ofthe instruction request user receives the user instruction datatransmitted from the information sharing apparatus 14 and transmits theuser instruction data to the control unit 20.

Then, the control unit 20 transmits the user instruction data to thedisplay control unit 26. Thus, the display control unit 26 transmits theuser instruction data to the display unit 21 and displays an instructionuser list image 81 on the display unit 21 based on the user instructiondata.

At this time, in the instruction user list image 81, information (names,nicknames, or the like) regarding plurality of other users to whom theinformation sharing apparatus 14 introduces the introduction requestuser is displayed.

Accordingly, the control unit 20 can introduce, to the introductionrequest user, the plurality of other users introduced from theinformation sharing apparatus 14 using the instruction user list image81.

At this time, when the introduction request user selects one of theother users as corresponding information on the instruction user listimage 81, the control unit 20 stores the user registration informationof the introduction request user and generates other user notificationdata indicating the selected other user.

Then, the control unit 20 transmits the other user notification data tothe transmission unit 23. In addition, the transmission unit 23transmits the other user notification data to the information sharingapparatus 14 via the network 13.

When the information sharing apparatus 14 receives the other usernotification data transmitted from the information display terminal 11,the information sharing apparatus 14 specifies the other users indicatedby the other user notification data and the introduction request user.

Based on the book association data between the specified other users andthe introduction request user, the information sharing apparatus 14generates book introduction data used to introduce single or a pluralityof electronic books that the introduction request user has not yetacquired among the electronic books that the other users have acquired.Then, the information sharing apparatus 14 transmits the bookintroduction data to the information display terminal 11 via the network13.

Accordingly, the reception unit 24 of the information display terminal11 of the introduction request user receives the book introduction datatransmitted from the information sharing apparatus 14 and transmits thebook introduction data to the control unit 20.

When the control unit 20 receives the book introduction data from thereception unit 24, the control unit 20 transmits the book introductiondata to the display control unit 26. In addition, the display controlunit 26 transmits the book introduction data to the display unit 21 anddisplays a book introduction image (not shown) on the display unit 21based on the book introduction data.

At this time, the book introduction image includes a book title, apublisher, a book kind, and book identification information of theelectronic book for each electronic book introduced from the informationsharing apparatus 14.

Accordingly, the control unit 20 can notifies the introduction requestuser of the single or plurality of electronic books introduced from theinformation sharing apparatus 14 through the book introduction image.

When the user selects a desired electronic book as information regardingthe book title or the like on the book introduction image, the controlunit 20 acquires the book attribute data such as the book title, thepublisher, the book kind, and the book identification information of theselected electronic book from the book introduction image.

Then, the control unit 20 stores the book attribute data, generatesacquisition request data used to give a request for acquiring theselected electronic book, and transmits the acquisition request data tothe transmission unit 23. In addition, the transmission unit 23transmits the acquisition request data to the information sharingapparatus or the electronic honk supply apparatus via the network 13.

As a consequence, when the electronic book data of the requestedelectronic book is transmitted from the information sharing apparatus orthe electronic book supply apparatus via the network 13, thetransmission unit 24 receives the electronic book data and transmits theelectronic book data to the control unit 20.

At this time, when the control unit 20 receives the electronic book datafrom the reception unit 24, the control unit 20 transmits the electronicbook data to store the electronic book data in the storage unit 25.Thus, the control unit 20 can newly acquire the electronic book usingthe book introduction image.

For example, when the control unit 20 receives a request for displayingthe electronic book from the user, the control unit 20 asks theinformation sharing apparatus 14 to supply the book association data inresponse to the end of the display of the electronic book.

In this case, in response to the end of the display of the electronicbook, the control unit 20 asks the retrieval unit 66 to sum up andretrieve the book association data of each desired part selected duringthe display of the electronic book.

Then, the control unit 20 allows the transmission unit 23 to transmitthe hook association data regarding all of the desired parts selectedduring the display of the electronic book to the information sharingapparatus 14. Thus, the control unit 20 can sum up the book associationdata regarding the desired parts, transmits the book association data tothe information sharing apparatus 14 to some degree to accumulate thebook association data.

2-2-6. Information Sharing Process

Next, an information sharing apparatus process will be described inwhich the control unit 20 shares various kinds of information regardingthe information display terminals 11 and 12 and the electronic books ofother users using the information sharing apparatus 14.

When the control unit 20 receives a request for acquiring informationregarding the desired parts selected by other users in the electronicbook in which the desired part is selected by the user, the control unit20 stores both the book identification information of the electronicbook and the user registration information and generates desired partinformation request data used to give a request for informationregarding the desired part in the following description, the informationregarding the desired part is also referred to as desired partinformation.

Then, the control unit 20 transmits the desired part information requestdata to the transmission unit 23. Thus, the transmission unit 23transmits the desired part information request data to the informationsharing apparatus 14 via the network 13.

At this time, when the information sharing apparatus 14 receives thedesired part information request data, the information sharing apparatus14 extracts the book identification information and the userregistration information stored in the desired part information requestdata.

Moreover, the information sharing apparatus 14 specifies the bookassociation data of the other users based on the book identificationinformation and the user registration information and also specifiessingle or a plurality of book association data of the electronic booksidentified with the book identification information among the specifiedbook association data.

The information sharing apparatus 14 finally returns the single orplurality of specified book association data to the information displayterminal 11 via the network 13.

At this time, the reception unit 24 of the information display terminal11 receives the single or plurality of book association data transmittedfrom the information sharing apparatus 14 and transmits the single orplurality of book association data to the control unit 20. When thecontrol unit 20 receives the single or plurality of book associationdata from the reception unit 24, the control unit 20 extracts thedesired part registration data and the book identification informationfrom one of the book association data.

Then, the control unit 20 extracts, from the desired part registrationdata, the page number and the desired part position informationindicating the position of a single or one of plurality of desired partsin the whole book text. Moreover, the control unit 20 generates emphasisdisplay control data used to control emphasis and display of the desiredpart based on the desired part position information.

Then, the control unit 20 reads the corresponding electronic book datafrom the storage unit 25 based on the book identification informationand transmits the read electronic book data together with the pagenumber and the emphasis display control data to the display control unit26.

When the display control unit 26 receives the electronic book datatogether with the page number and the emphasis display control data fromthe control unit 20, the display control unit generates electronic bookimage data of the page indicated by the page number based on theelectronic book image data. Then, the display control unit 26 processesthe electronic book image data based on the emphasis display controldata and transmits the processed electronic book image data to thedisplay unit 21.

Thus, the display control unit 26 displays the electronic book imagewhich is based on the electronic book image data on the display unit 21and displays the desired parts selected by the other users in the textof the electronic book image in the emphasis manner.

Thus, the control unit 20 can introduce the desired parts selected bythe other users to the user using the electronic book image. At thistime, when the desired part is instructed on the electronic book image,the control unit 20 displays the tags on the electronic book image, asdescribed above.

Moreover, when the tags are instructed on the electronic book image, thecontrol unit 20 also displays the association comments (that is, theassociation comments input by the other users) and the like added to thetags.

Furthermore, the control unit 20 can likewise display the differentdesired parts selected by the other users in the emphasis manner inresponse to change (change in the page) in the display of the electronicbook image and can display the tags or the association comments.

Thus, the control unit 20 can show the user how the other users selectthe desired parts in the electronic book which the user has selected.

In particular, the information sharing apparatus 11 can accumulate thebook association data regarding the same electronic book translated ineach country and the control unit 20 can inform the user of theviewpoints of foreign readers when the control unit 20 can identify theaccumulated book association data as the book association data of thesame book.

Moreover, the control unit 20 can communicate with the other informationdisplay terminals 11 and 12. Therefore, the control unit 20 can performa process of reflecting the selected desired parts without theinformation sharing apparatus 14 by directly communicating with theother information display terminals 11 and 12.

The control unit 20 can reflect the selection of the desired part in theelectronic book image by communicating the own information displayterminal 12 mutually acquiring the same electronic book with single or aplurality of information display terminals 11 and 12.

In this case, in response to a predetermined operation of the user, thecontrol unit 20 sets the addresses of the single or plurality ofdifferent information display terminals 11 and 12 which arecommunication opponents.

The control unit 20 reads, from the storage unit 25, the electronic bookdata of the same electronic book as the electronic book displaying theinformation display terminals 11 and 12 which are the communicationopponents and transmits the electronic honk data to the display controlunit 26.

Thus, the display control unit 26 generates the electronic book imagedata based on the electronic book data and transmits the generatedelectronic book image data to the display unit 21 to display theelectronic book image on the display unit 21.

In this state, when the desired part is instructed on the electronicbook image, the control unit 20 performs the series of processes, suchas the process of specifying and registering the desired part from thedetection of the instruction estimated part, the process of detectingthe keywords, the process of generating the tags, and the process ofregistering and associating the keywords and the tags, in cooperationwith each circuit unit, as described above.

When the series of processes is completed, the control unit 20 allowsthe retrieval unit 66 to retrieve and acquire the book association dataregarding the selected desired parts. Then, the control unit 20transmits the book association data to the transmission unit 23.

At this time, the transmission unit 23 adds the previously set addressesof the other information display terminals 11 and 12 to the bookassociation data transmitted from the control unit 20. Then, thetransmission unit 23 transmits the hook association data, to which theaddresses are added, and the user registration information to theinformation sharing apparatus 14 via the network 13.

At this time, the information sharing apparatus 14 receives the bookassociation data and the user registration information transmitted fromthe information display terminal 11 and transmits the book associationdata to the other information display terminals 11 and 12 based on theaddresses added to the book association data.

The control unit 20 can notify the other information display terminals11 and 12 of the desired part selected by the user and the otherkeywords, tags, or the like regarding the desired part using the bookassociation data.

On the other hand, when the book association data is transmitted fromthe other information display terminals 11 and 12 via the informationsharing apparatus 14 in response to the user selection of the desiredpart, the reception unit 24 receives the book association data andtransmits the book association data to the control unit 20.

When the control unit 20 receives the book association data from thereception unit 24, based on the book association data, the control unit20 determines whether the page of the electronic book image beingcurrently displayed on the display unit 21 is identical to the page ofthe electronic book image in which the desired part is selected byanother user.

As a consequence, when the control unit 20 determines that the page ofthe electronic book image being currently displayed on the display unit21 is identical to the page of the electronic book image in which thedesired part is selected by another user, the control unit 20 generatesthe emphasis display control data used to display the desired part inthe emphasis manner based on the book association data. Then, thecontrol unit 20 transmits the emphasis display control data to thedisplay control unit 26.

Thus, based on the emphasis display control data, the display controlunit 26 displays the desired part selected by another user in theemphasis manner in the electronic book image being currently displayedon the display unit 21.

At this time, when the desired part selected by another user isinstructed on the electronic book image, the control unit 20 displaysthe tag on the electronic book image, as described above.

Moreover, when the tag is instructed on the electronic book image, thecontrol unit 20 displays the association comment (that is, theassociation comment input by another user) and the like added to thetag.

On the other hand, even when the page of the electronic book image beingcurrently displayed on the display unit 21 is different from the page ofthe electronic book image in which the desired part is selected byanother user, the control unit 20 performs the determination processperformed when the electronic book image being displayed is newlyswitched.

Thus, the control unit 20 displays the desired part in the emphasismanner when the same electronic book image as the electronic book imagein which the desired part is selected by another user is displayed onthe display unit 21.

As shown in FIG. 34, the control unit 20 can reflect the selection ofthe desired part in the electronic book image of the same electronicbook in nearly real time for the own information display terminal 12 andthe single or plurality of other information display terminals 11 and12.

For example, when the function of reflecting the desired part isutilized in displaying an electronic book for a learning textbook, thecontrol unit 20 can show the users mutual learning methods, a differencein the viewpoints of the attention, or the like, thereby sufficientlyexerting this function.

When the control unit 20 acquires the book association data from theinformation sharing apparatus 14 or the other information displayterminals 11 and 12, the control unit 20 stores the book associationdata in the storage unit 25.

Accordingly, when the book association data is stored in the storageunit 25 and another user subsequently selects the desired part in thetext of the electronic honk image being displayed, the control unit 20can display the desired part in the emphasis manner based on the bookassociation data.

When the control unit 20 displays the desired parts in the emphasismanner in a case where there are the desired parts respectively selectedby other users different from the user in the text of one electronicbook image, there is the concern that is difficult to determine whoselects the desired parts.

Accordingly, when the user executes a predetermined operation to give arequest for displaying an emphasis display menu image in the state wherethe electronic book image is displayed, the control unit 20 readsemphasis display menu image data stored in advance in the storage unit25 and transmits the emphasis display menu image data to the displaycontrol unit 26.

Then, the display control unit 26 synthesizes the emphasis display menuimage data transmitted from the control unit 20 with the generatedelectronic book image data and transmits the synthesized data to thedisplay unit 21. As shown in FIG. 35, the display control unit 26displays an emphasis display menu image 82 on a part of the electronicbook image 81 in an overlapping manner on the display unit 21.

In this case, in the emphasis display menu image 82, various buttons aredisposed to give instructions of classifying the desired parts based onthe attributes of the desired parts and switching the display states ofthe emphasis displays of the desired parts in accordance with theclassification.

That is, in the emphasis display menu image 82, an automatic generationtag use change button 83 is disposed to classify the desired parts addedwith the tags in accordance with the tags automatically generated andchange the display state of the emphasis display for each tag.

In the emphasis display menu image 82, a user selection tag use changebutton 84 is also disposed to classify the desired parts added with thetags in accordance with the tags selected by the user and change thedisplay state of the emphasis display for each tag.

In the emphasis display menu image 82, a person use change button 85 isalso disposed to classify the desired parts in accordance with a personselecting the desired part and change the display state of the emphasisdisplay for each person.

In the emphasis display menu image 82, an importance degree use changebutton 86 is also disposed to classify the desired parts in accordancewith an importance degree and change the display state of the emphasisdisplay in accordance with the importance degree.

Accordingly, when the user executes a tap operation to instruct theperson use change button 85 of the emphasis display menu image 82, thecontrol unit 20 classifies the desired parts across the whole book textof the electronic book to be displayed in accordance with the personselecting the desired part. The control unit 20 performs setting ofchanging the display state of the emphasis display of the desired partfor each person.

Thus, the control unit 20 can easily distinguish the desired parts, evenwhen the desired part selected by the user and the desired part selectedby another user coexist in the electronic book image 81 being displayed.

When the user executes a tap operation to instruct the automaticgeneration tag use change button 83 of the emphasis display menu image82, the control unit 20 classifies the desired parts across the wholebook text of the electronic book to be displayed in accordance with themeaning of the automatically generated tag. The control unit 20 performssetting of changing the display state of the emphasis display of thedesired part for the meaning indicated by the tag.

Thus, the control unit 20 can easily distinguish the desired parts, whenthe desired parts attached with different tags coexist in the electronicbook image 81 being displayed.

When the user executes a tap operation to instruct the user selectiontag use change button 84 of the emphasis display menu image 82, thecontrol unit 20 classifies the desired parts across the whole book textof the electronic book to be displayed in accordance with the kinds(learning, a small terminal, and the like) of tags selected by the user.The control unit 20 performs setting of changing the display state ofthe emphasis display of the desired part for the kinds of tags.

In this case, as for the desired part added with no tag selected by theuser, the control unit 20 displays this desired part in the emphasismanner in a display state different from the emphasis display of thedesired part added with the tag selected by the user.

Thus, the control unit 20 can easily distinguish the desired parts, evenwhen the desired parts added with the different kinds of tagsarbitrarily selected by the user coexist in the electronic book image 81being displayed.

When the user executes a tap operation to instruct the importance degreeuse change button 86 of the emphasis display menu image 82, the controlunit 20 detects the appearance degree of the keyword identical to thekeyword included in the desired part in the whole book text.

At this time, the control unit 20 also detects the number of associationbooks detected with the keyword included in the desired part. Moreover,the control unit 20 also detects the number of keywords included in thedesired part.

Based on the detection result of each desired part, the control unit 20calculates the importance degrees (that is, which is a value serving asan index representing how important the desired part is when the userreads and comprehends the electronic book) of the respective desiredparts.

The control unit 20 classifies the desired parts in accordance with theimportance degrees and performs setting of changing the display state ofthe emphasis display of the desired parts for each importance degree.

Thus, when the plurality of desired parts coexist in the electronic bookimage 81 being displayed, the control unit 20 can easily determine howimportant the desired part is when the user reads and comprehends theelectronic book.

When the user instructs the importance degree use change button 86, thecontrol unit 20 reads relation notification image data, which indicatesa relation between the importance degree and the display state of theemphasis display and is stored in advance in the storage unit 25, andtransmits the relation notification image data to the display controlunit 26.

When the display control unit 26 receives the relation notificationimage data from the control unit 20, the display control unit 26synthesizes the electronic book image data, the emphasis display menuimage data, and the relation notification image data and transmits thesynthesized data to the display unit 21.

As shown in FIG. 36, the display control unit 26 overlaps the emphasisdisplay menu image 82 on a part of the electronic book image 81 on thedisplay unit 21 and displays a relation notification image 37 in anotherpart of the electronic book image 81 in an overlapping manner.

Accordingly, the control unit 20 can permit the user to exactlyrecognize which desired part is more important and which desired part isless important by the relation notification image.

For example, when the user gives a request for generating a test problembased on the desired part in the state where the display state of theemphasis display is changed in accordance with the importance degree ofthe desired part, the control unit 20 allows the retrieval unit 66 todetect the score of the keyword included in the desired part for eachdesired part.

The control unit 20 specifies the keyword to which the score equal to orgreater than a predetermined number selected in advance is assigned foreach desired part. In the following description, the specified keywordis also referred to as a specific keyword.

The control unit 20 generates concealing data used to conceal thespecific keyword in the individual desired part using a specificcharacter string which indicates a test problem for replying thespecific keyword.

The control unit 20 compares the importance degree of the desired partwith the predetermined value selected in advance. As a consequence, whenthe control unit 20 detects the desired part with the importance degreeequal to or greater than the predetermined value (the importance degreeis high), the control unit 20 selects one or more words similar to atleast a part of the specific keyword of the detected desired part basedon, for example, word dictionary data stored in advance in the storageunit 25.

The control unit 20 generates a character string for which at least apart of the specific keyword is substituted by a selected word.Moreover, the control unit 20 generates option introduction image dataindicating the specific keyword and single or a plurality of characterstrings for which at least a part of the specific keyword is substitutedby another word.

Thus, when the control unit 20 generates the concealing data or theoption introduction image data for the test problem, the control unit 20transmits the concealing data or the option introduction image datatogether with positional information indicating the disposition positionin the text and the display position on the electronic book image to thedisplay control unit 26.

When the display control unit 26 receives the concealing data or theoption introduction image data together with the positional informationfrom the control unit 20, the display control unit 26 processes theelectronic book image based on the concealing data or the optionintroduction image data and the positional information and transmits theprocessed data to the display unit 21.

Thus, the display control unit 26 displays an electronic book image 90processed for a test problem shown in FIG. 37 on the display unit 21 andalso displays an option instruction image 91 at a predetermined positionon the electronic book image 90.

Here, for example, the electronic book image 90 processed for the testproblem is concealed by a character string 92 indicating the testproblem that expresses that the specific keyword is “Question 1?” so asto reply the specific keyword in the desired part.

On the electronic book image 90 processed for the test problem, anoption introduction image 91 used to select and rely the specifickeyword of the desired part among the plurality of options is displayedin an overlapping manner in the vicinity of the desired part with thehigh importance degree.

Thus, the control unit 20 can automatically generate and show the testproblem to the user using the electronic book image so that the user cansolve the test problem. In particular, when the control unit 20 performsa test problem automatic generation function of automatically generatingand showing such a test problem, for example, in a case where theelectronic book for a learning textbook is displayed, the test problemautomatic generation function can be sufficiently utilized.

For example, when user permits display of an advertisement in a casewhere the control unit 20 displays the electronic book image includingthe desired part in the text, the control unit 20 allows the retrievalunit 66 to retrieve and read the keyword included in the desired partfrom the storage unit 25.

Then, the control unit 20 stores the keyword, generates advertisementrequest data used to give a request for the advertisement, and transmitsthe advertisement request data to the transmission unit 23. At thistime, the transmission unit 23 transmits the advertisement request datatransmitted from the control unit 20 to an advertisement supplyapparatus (not shown) via the network 13.

Here, the advertisement supply apparatus stores plural kinds ofadvertisement image data in association with the keyword indicating thecontents of the advertisement. Accordingly, when the advertisementsupply apparatus receives the advertisement request data transmittedfrom the information display terminal 11, the advertisement supplyapparatus selects the advertisement image data corresponding to thekeyword among the plurality of advertisement image data based on thekeyword stored in the advertisement image data. Then, the advertisementsupply apparatus transmits the selected advertisement image data to theinformation display terminal 11 via the network 13.

At this time, the reception unit 24 of the information display terminal11 receives the advertisement image data transmitted from theadvertisement supply advertisement and transmits the advertisement imagedata to the control unit 20. Then, when the control unit 20 receives theadvertisement image data from the reception unit 24, the control unit 20transmits the advertisement image data to the display control unit 26.

Thus, the display control unit 26 synthesizes the advertisement imagedata transmitted from the control unit 20 and the electronic book imagedata, and transmits the synthesized data to the display unit 21, andthus displays an advertisement image based on the advertisement imagedata on a part of the electronic book image in an overlapping manner onthe display unit 21.

In this way, the control unit 20 can show an advertisement associatedwith the desired part on the electronic book image to the user using theadvertisement image in cooperation with the advertisement supplyapparatus.

2-3. Hardware Configuration of Function Circuit Block of OtherInformation Display Terminal

Next, the hardware configuration of a function circuit block of theother information display terminal 12 between two kinds of informationdisplay terminals 11 and 12 will be described with reference FIG. 38.The reference numerals are given to the constituent elementscorresponding to the elements in FIG. 3.

The information display terminal 12 has no natural language processingblock and has the same configuration as that of the information displayterminal 11 described above except for the configuration of anacquisition unit 100.

In this case, when the acquisition unit 100 receives the instructionestimated part data to be analyzed and the book attribute data from theselection unit 28, the acquisition unit 100 temporarily maintains theinstruction estimated part data and the book attribute data. Then, theacquisition unit 100 stores the instruction estimated part data to beanalyzed, generates analysis request data used to ask the informationsharing apparatus 14 to analyze the instruction estimated part data, andtransmits the analysis request data to the transmission unit 23.

Then, the transmission unit 23 transmits the analysis request datatransmitted from the acquisition unit 100 to the information sharingapparatus 14 via the network 13. At this time, when the informationsharing apparatus 14 receives the analysis request data transmitted fromthe information display terminal 112, the information sharing apparatus14 analyzes the instruction estimated part data stored in the analysisrequest data, as in the natural language processing block 30 describedabove.

The information sharing apparatus 14 transmits estimated part analysisresult data indicating the analysis result of the instruction estimatedpart data to the information display terminal 12 via the network 13.Accordingly, the reception unit 24 receives the estimated part analysisresult data transmitted from the information sharing apparatus 14 andtransmits the received estimated part analysis result data to theacquisition unit 100.

When the acquisition unit 100 receives the estimated part analysisresult data from the reception unit 24, the acquisition unit 100transmits the estimated part analysis result data together with thetemporarily maintained instruction estimated part data And the hookattribute data to the specifying unit 33.

In this way, the acquisition unit 100 basically performs the sameprocess as that of the acquisition unit 29 of the information displayterminal 11 described above, except for the fact that acquisition unit100 asks the information sharing apparatus 14 to analyze the instructionestimated part data and the entire text data to be analyzed.

2-4. Hardware Configuration of Function Circuit Block of InformationSharing Apparatus

Next, the hardware configuration of the function circuit block of aninformation sharing apparatus 14 will be described with reference toFIG. 39.

As shown in FIG. 39, the other information shoring apparatus 14 includesa control unit 110 that controls the information sharing apparatus 14 asa whole. The information sharing apparatus 14 includes a storage unit111. For example, the storage unit 111 stores the electronic book dataof a plurality of electronic books.

The control unit 110 performs the user registration to register users bytransmitting user registration information, such as the names ornicknames of the users giving a request for the user registration andthe addresses of the information display terminals 11 and 12 used by theusers, to the storage unit 111 and by storing the user registrationinformation. Thus, the control unit 110 permits the registered users touse the information sharing apparatus 14.

In this state, when the acquisition request data are transmitted fromthe information display terminal 11 and the 12 via the network 13, thereception unit 112 receives the acquisition request data and transmitsthe acquisition request data to the control unit 110.

When the control unit 110 receives the acquisition request data from thereception unit 112, the control unit 110 reads the electronic book dataof the electronic book asked by the user from the storage unit 111 andtransmits the read electronic book data to a transmission unit 113.

The transmission unit 113 transmits the electronic book data transmittedfrom the control unit 110 to the information display terminals 11 and 12asking the acquisition of the electronic book via the network 13. Thus,the control unit 110 can supply the electronic book data to theinformation display terminals 11 and 12.

When the book association data and the user registration information aretransmitted from the information display terminals 11 and 12 via thenetwork 13, the reception unit 112 receives the book association dataand the user registration information and transmits the book associationdata and the user registration information to the control unit 110.

At this time, the control unit 110 stores the book association data andthe user registration information in association with the bookassociation data and the user registration information in the storageunit 111 by transmitting the book association data and the userregistration information from the reception unit 112 to the storage unit111.

Thus, the control unit 110 accumulates, as the book association data,information regarding the desired part selected in the text of theelectronic book by each of the plurality of users or various kinds ofinformation regarding the electronic book in a manageable state for eachuser.

When the instruction request data are transmitted from the informationdisplay terminals 11 and 12 via the network 13, the reception unit 112receives the instruction request data and transmits the instructionrequest data to a filtering processing unit 114 via the control unit110.

When the filtering processing unit 114 receives the instruction requestdata from the reception unit 112, the filtering processing unit 114extracts the user registration information from the instruction requestdata. Moreover, the filtering processing unit 114 reads the bookassociation data (of the introduction request user) associated with theuser registration information from the storage unit 111.

The filtering processing unit 114 also reads the hook association dataof the user different from the introduction request user indicated bythe user registration information from the storage unit 111. Moreover,the filtering processing unit 114 performs a cooperation filteringprocess using the book association data of the introduction request userand the electronic book data of another user.

Thus, the filtering processing unit 114 specifies another user havingacquired the same electronic book as that of the introduction requestuser. Moreover, since the preference of the introduction request user issimilar from the specified user, the filtering processing unit 114narrows the other users having acquired the electronic books differentfrom that of the introduction request user.

The filtering processing unit 114 generates the user introduction dataindicating the narrowed other users and transmits the generated userintroduction data to the transmission unit 113. Accordingly, thetransmission unit 113 transmits the user introduction data to theinformation display terminals 11 and 12 via the network 13. Thus, thefiltering processing unit 114 can introduce the users having the similarpreference to the introduction request user.

When the other user notification data are transmitted from theinformation display terminals 11 and 12 via the network 13, thereception unit 112 receives the other user notification data andtransmits the other user notification data to the filtering processingunit 114 via the control unit 110.

When the filtering processing unit 114 receives the other usernotification data from the reception unit 112, the filtering processingunit 114 specifies the other users indicated by the other usernotification data and the introduction request user. Moreover, thefiltering processing unit 114 reads the book association data betweenthe specified other users and the specified introduction request userfrom the storage unit 111.

Based on the book association data between the specified other users andthe specified introduction request user, the filtering processing unit114 generates the book introduction data used to introduce single or aplurality of electronic books which the introduction request user hasnot acquired among the electronic books which the other users haveacquired.

Then, the filtering processing unit 114 transmits the book introductiondata to the transmission unit 113. Thus, the transmission unit 113transmits the book introduction data to the information displayterminals 11 and 12 of the introduction request users via the network13.

Thus, the filtering processing unit 114 can introduce, to theintroduction request user, the electronic books which the introductionrequest user has not acquired and the other users having the similarpreference have acquired.

When the desired part information request data are transmitted from theinformation display terminals 11 and 12 via the network 13, thereception unit 112 receives the desired part information request dataand transmits the desired part information request data to the controlunit 110.

When the control unit 110 receives the desired part information requestdata from the reception unit 112, the control unit 110 extracts the bookidentification information and the user registration information storedin the desired part information request data.

Based on the book identification information and the user registrationinformation, the control unit 110 retrieves and reads single or aplurality of book association data identified with the bookidentification information among the book association data of the otherusers from the storage unit 111. Then, the control unit 110 transmitsthe single or plurality of book association data to the transmissionunit 113.

The transmission unit 113 transmits the single or plurality of bookassociation data transmitted from the control unit 110 to theinformation display terminals 11 and 12 via the network 13. Thus, thecontrol unit 110 can inform the user how the other users selects thedesired part from the electronic book in which the own user has selectedthe desired part.

When the reception unit 112 receives the book association data, thecontrol unit 110 stores and accumulates the book association data in thestorage unit 111, as described above. However, when the addresses areadded to the book association data, the control unit 110 also transmitsthe book association data to the transmission unit 113.

The transmission unit 113 transmits the book association datatransmitted from the control unit 110 to the information displayterminals 11 and 12 indicated by the addresses via the network 13 inaccordance with the addresses added to the book association data.

Thus, the control unit 20 can reflect and share the desired part, whenthe desired part is selected by the respective users between theplurality of information display terminals 11 and 12.

2-5. Emphasis Display Processing Sequence

Next, an emphasis display processing sequence RT1 will be described inwhich the control unit 20 of the information display terminals 11 and 12displays the desired part in the emphasis manner in response of theselection of the desired part in the text of the electronic book withreference to FIGS. 40 to 45.

For example, when the control unit 20 displays an electronic book imageon the display unit 21 in response of a request for displaying anelectronic book, the control unit 20 starts the emphasis displayprocessing sequence RT1 shown in FIG. 40 in cooperation with eachcircuit unit.

When the control unit 20 starts the emphasis display processing sequenceRT1, the control unit 20 determines whether the desired part isinstructed in the text of the electronic book image being displayed onthe display unit 21.

When a negative result is obtained in step SP1, for example, thenegative result indicates that the user is reading the text of theelectronic book image. When the control unit 20 obtains the negativeresult in step SP1, the process proceeds to step SP2.

In step SP2, the control unit 20 determines whether the display of theelectronic book ends. When a negative result is obtained in step SP2,for example, the negative result indicates the user continues readingthat the text of the electronic book image. When the control unit 20obtains the negative result in step SP2, the process returns to stepSP1.

While the control unit 20 displays the electronic book image, step SP1and step SP2 are circularly repeated. In addition, the control unit 20waits until the desired part is instructed in the text of the electronicbook image being displayed or a request for ending the display of theelectronic book is given.

On the other hand, when a positive result is obtained in step SP1, thepositive result indicates that the user reading the text of theelectronic book being displayed executes a slide operation to instructthe desired part which the user is interested in.

When the control unit 20 obtains the positive result in step SP1, thecontrol unit 20 generates the region correspondence text data based onthe electronic book image and transmits the region correspondence textdata together with the determination result of the kind of the slideoperation and the touch position information to the selection unit 28.

Accordingly, in step SP3, the selection unit 28 performs an instructionestimated part selection process of selecting the instruction estimatedpart instructed by the user from the text of the electronic bookindicated by the region correspondence text data based on thedetermination result of the kind of the slide operation and the touchposition information.

Thus, the selection unit 28 selects the instruction estimated part fromthe text, generates the instruction estimated part data indicating theselection result of the instruction estimated part, and transmits thegenerated instruction estimated part data to the acquisition unit 29.

In step SP4, the acquisition unit 29 acquires the analysis result of theinstruction estimated part data for the natural language processingusing the natural language processing block 30 or the informationsharing apparatus 14 and transmits the analysis result to the specifyingunit 33.

In step SP5, the specifying unit 33 specifies the desired part in theinstruction estimated part based on the analysis result of theinstruction estimated part obtained based on the instruction estimatedpart data.

The specifying unit 33 generates the desired part data indicating thespecified desired part and generates the desired part analysis resultdata indicating the analysis result of the desired part based on theestimated part analysis result data.

The specifying unit 33 transmits the desired part data to theregistration unit 34 and transmits the desired part data and the desiredpart analysis result data to the detection unit 35.

In step SP6, the registration unit 34 registers the desired partselected by the user in the desired part registration table DT2 of thestorage unit 25 based on the desired part data.

In step SP7, the detection unit 35 performs a keyword detection processof detecting the keywords from the desired part, which is based on thedesired part data, based on the analysis result of the desired partobtained based on the desired part analysis result data. Then, thedetection unit 35 transmits the keyword detection data indicating thedetection result of the keywords detected from the desired part to thetag generation unit 36.

In step SP8, the tag generation unit 36 performs a tag generationprocess of generating the tag of the desired part based on the keyworddetection data. Thus, the tag generation unit 36 generates the tag ofthe desired part.

In step SP9, the control unit 20 displays the desired part selected inthe text of the electronic book image being displayed in the emphasismanner in response to the specifying of the desired part performed bythe instruction of the desired part, the detecting of the keyword, andthe ending of the tag generation. Then, the process proceeds to stepSP2.

Thus, whenever the user instructs the desired part in the text of theelectronic book image, the control unit 20 sequentially performs theprocesses from step SP3 to step SP9 in cooperation with each circuitunit.

When a positive result is obtained in step SP2, the positive resultindicates that the user gives a request for ending the display of theelectronic book. When the control unit 20 obtains the positive result instep SP2, the process proceeds to step SP10 and the emphasis displayprocessing sequence RT1 ends.

When the process proceeds from step SP1 to step SP2 in the emphasisdisplay processing sequence RT1 described above, the selection unit 28starts a sub-routine SRT1 of the instruction estimated part selectionprocess shown in FIGS. 41 to 43.

When the sub-routine SRT1 of the instruction estimated part selectionprocess starts, the selection unit 28 detects the instruction range inthe text of the electronic book image based on the kind of slideoperation and the touch position at the time at which the desired partis instructed in step SP101. Next, the process proceeds to step SP102.

In step SP102, the selection unit 28 determines whether the method ofselecting the instruction estimated part is set currently in accordancewith the first selection method. When a positive result is obtained instep SP102, the positive result indicates that the user tends toinstruct a part larger than the actual desired part in the text. Whenthe selection unit 28 obtains the positive result in step SP102, theprocess proceeds to step SP103.

In step SP103, the selection unit 28 detects the front referencecharacter located at the intersection point between the uppermost onerow and the leftmost one column of the character string of theinstruction range. The selection unit 28 also detects the rear referencecharacter located at the intersection point between the lowermost onerow and the rightmost one column of the character string of theinstruction range. Next, the process proceeds to step SP104.

In step SP104, the selection unit 28 sets the search range from thefront reference character to the rear reference character of the text ofthe electronic book image as the search range. Next, the processproceeds to step SP105.

In step SP105, the selection unit 28 searches for the separationcharacter while sequentially determining the kinds of character from thefront reference character to the finishing side. Next, the processproceeds to step SP106.

In step SP106, the selection unit 28 determines whether the separationcharacter is detected within the search range. At this time, when theselection unit 28 detects the separation character within the searchrange and thus obtains a positive result, the process proceeds to stepSP107.

In step SP107, the selection unit 28 searches for the separationcharacter while sequentially determining the kinds of characters fromthe rear reference character to the beginning side. When the selectionunit 28 detects the separation character, the process proceeds to stepSP108.

In step SP108, the selection unit 28 determines whether the separationcharacter detected in the search from the front reference character isdifferent from the separation character detected in the search from therear reference character. When a positive result is obtained in stepSP108, the positive result indicates that at least one phrase or clauseis included within the search range. When the selection unit 28 obtainsthe positive result in step SP108, the process proceeds to step SP109.

In step SP109, the selection unit 28 selects the character string fromone separation character to the other separation character detected inthe search of the search range from the text, and then process proceedsto step SP110. In step SP110, the selection unit 28 ends the sub-routineSRT1 of the instruction estimated selection process.

On the other hand, when the selection unit 28 does not detect theseparation character within the search range and thus obtains a negativeresult in step SP106, the process proceeds to step SP111.

When a negative result is obtained in step SP108, for example, thenegative result indicates that only one separation character is includedin the sentence or the phrase within the search range. When theselection unit 28 obtains the negative result in step SP108, the processalso proceeds to step SP111.

In step SP111, the selection unit 28 selects the character string fromthe front reference character to the rear reference character as theinstruction estimated part from the text, and then the process proceedsto step SP110. In step SP110, the selection unit 28 ends the sub-routineSRT1 of the instruction estimated selection process.

On the other hand, when a negative result is obtained in step SP102, thenegative result indicates that the user tends to instruct a partnarrower than the actual desired part in the text or the user tends toinstruct a part narrower or larger than the desired part. When theselection unit 28 obtains the negative result in step SP102, the processproceeds to step SP112.

In step SP112, the selection unit 28 determines whether the method ofselecting the instruction estimated part is set currently in accordancewith the second selection method. When a positive result is obtained instep SP112, the positive result indicates that the user tends toinstruct a part narrower than the actual desired part in the text. Whenthe selection unit 28 obtains the positive result in step SP112, theprocess proceeds to step SP113.

In step SP113, the selection unit 28 detects the front referencecharacter located at the intersection point between the uppermost onerow and the leftmost one column of the character string of theinstruction range. The selection unit 28 also detects the rear referencecharacter located at the intersection point between the lowermost onerow and the rightmost one column of the character string of theinstruction range. Next, the process proceeds to step SP114.

In step SP114, the selection unit 28 sets the search range from thefront reference character of the text of the electronic book image tothe front character of the display range as the beginning search range.Moreover, the selection unit 28 sets the rear reference character in thetext of the electronic book image to the rear character of the displayrange as the finishing search range. Next, the process proceeds to stepSP115.

In step SP115, the selection unit 28 searches for the separationcharacter while sequentially determining the kinds of character from thefront reference character to the front character of the display range.Next, the process proceeds to step SP116.

In step SP116, the selection unit 28 determines whether the separationcharacter is detected within the beginning search range. At this time,when the selection unit 28 detects the separation character within thebeginning search range and thus obtains a positive result, the processproceeds to step SP117.

In step SP117, the selection unit 28 searches for the separationcharacter while sequentially determining the kinds of characters fromthe rear reference character to the rear character of the display range.Next, the process proceeds to step SP118.

In step SP118, the selection unit 28 determines whether the separationcharacter is detected in the finishing search range. When the selectionunit 28 detects the separation character within the finishing searchrange and thus obtains a positive result, the process proceeds to stepSP119.

In step SP119, the selection unit 28 selects the character string fromthe separation character detected within the beginning search range tothe separation character detected in the finishing search range from thetext, and then process proceeds to step SP110. In step SP110, theselection unit 28 ends the sub-routine SRT1 of the instruction estimatedselection process.

On the other hand, when the selection unit 28 does not detect theseparation character within the beginning search range and thus obtainsa negative result in step SP116, the process proceeds to step SP120.

On the other hand, when the selection unit 28 does not detect theseparation character within the finishing search range and thus obtainsa negative result in step SP118, the process proceeds to step SP120.

In step SP120, the selection unit 28 selects the character string of apredetermined range as the instruction estimated part from the text inaccordance with the detailed setting of the second selection method, andthen the process proceeds to step SP110. In step SP110, the selectionunit 28 ends the sub-routine SRT1 of the instruction estimated selectionprocess.

On the other hand, when a negative result is obtained in step SP112, thenegative result indicates that the user tends to instruct a partnarrower or larger than the actual desired part in the text and thus thethird selection method is set in consideration of this tendency. Whenthe selection unit 28 obtains the negative result in step SP112, theprocess proceeds to step SP121.

In step SP121, the selection unit 28 detects the front referencecharacter located at the intersection point between the uppermost onerow and the leftmost one column of the character string of theinstruction range. The selection unit 28 also detects the rear referencecharacter located at the intersection point between the lowermost onerow and the rightmost one column of the character string of theinstruction range. Next, the process proceeds to step SP122.

In step SP122, the selection unit 28 sets the search range from thefront reference character to the rear reference character of the text ofthe electronic book image as the search range. Next, the processproceeds to step SP123.

In step SP123, the selection unit 28 searches for the separationcharacter while sequentially determining the kinds of character from thefront reference character to the finishing side. Next, the processproceeds to step SP124.

In step SP124, the selection unit 28 determines whether the separationcharacter is detected within the search range. At this time, when theselection unit 28 detects the separation character within the searchrange and thus obtains a positive result, the process proceeds to stepSP125.

In step SP125, the selection unit 28 searches for the separationcharacter while sequentially determining the kinds of characters fromthe rear reference character to the beginning side. When the selectionunit 28 detects the separation character, the process proceeds to stepSP126.

In step SP126, the selection unit 28 determines whether the separationcharacter detected in the search from the front reference character isdifferent from the separation character detected in the search from therear reference character. When a positive result is obtained in stepSP126, the positive result indicates that at least one phrase or clauseis included within the search range. When the selection unit 28 obtainsthe positive result in step SP126, the process proceeds to step SP127.

In step SP127, the selection unit 28 selects the character string fromone separation character to the other separation character detected inthe search of the search range from the text, and then process proceedsto step SP110. In step SP110, the selection unit 28 ends the sub-routineSRT1 of the instruction estimated selection process.

On the other hand, when the selection unit 28 does not detect theseparation character within the search range and thus obtains a negativeresult in step SP124, the process proceeds to step SP128. At this time,in step SP128, the selection unit 28 selects the character string fromfront reference character to the rear reference character from the textas the instruction estimated part, and then process proceeds to stepSP110. In step SP110, the selection unit 28 ends the sub-routine SRT1 ofthe instruction estimated selection process.

When a negative result is obtained in step SP126, for example, thenegative result indicates that only one separation character is includedin the sentence or the phrase within the search range. When the negativeresult is obtained in step SP126, the selection unit 28 also allows theprocess to proceed to step SP129.

In step SP129, the selection unit 28 selects the character string of apredetermined range as the instruction estimated part from the text inaccordance with the setting of the third selection method, and then theprocess proceeds to step SP110. In step SP110, the selection unit 28ends the sub-routine SRT1 of the instruction estimated selectionprocess.

When the process proceeds from sep SP6 to step SP7 in the emphasisdisplay processing sequence RT1 described above, the detection unit 35starts a sub-routine SRT2 of a keyword detection process shown in FIG.44.

When the sub-routine SRT2 of the keyword detection process starts, thedetection unit 35 detects the keyword from the desired part based on theanalysis result of the desired part in step SP201. Next, the processproceeds to step SP202.

In step SP202, the detection unit 35 detects the meaning of the keywordbased on the analysis result of the desired part. Next, the processproceeds to step SP203.

In step SP203, the detection unit 35 assigns the score to the keywordbased on the appearance frequency and the modification of the keyword inthe desired part.

In step SP204, the registration unit 34 registers the keyword, themeaning, and the score detected by the detection unit 35 in the keywordregistration table DT3 of the storage unit 25.

In step SP205, the association unit 60 associates the keyword registeredby the registration unit 34 with the desired part using the keywordassociation table DT5 of the storage unit 25. Thus, the detection unit35 allows the process to proceed to the step SP206 and ends thesub-routine SRT2 of the keyword detection process.

When the process proceeds from step SP7 to step SP8 in the emphasisdisplay processing sequence RT1 described above, the tag generation unit36 starts a sub-routine SRT3 of the tag generation process shown in FIG.45.

When the sub-routine SRT3 of the tag generation process starts, the taggeneration unit 36 analyzes the meaning of the keyword detected by thedetection unit 35 in step SP301. Next, the process proceeds to stepSP302.

In step SP302, the tag generation unit 36 automatically generates thetag of the desired part based on the analyzed meaning. Next, the processproceeds to step SP303.

In step SP303, the tag generation unit 36 assigns the score to the tagbased on the number of keywords having the meaning used as the tag.

In step SP304, the registration unit 34 registers the tag generated bythe tag generation unit 36 in the tag registration table DT4 of thestorage unit 25.

In step SP305, the association unit 60 associates the tag registered bythe registration unit 34 with the desired part wing the tag registrationtable DT6 of the storage unit 25 and registers the score and the tag inassociation with associates the score of the tag and the tag. Thus, thetag generation unit 36 allows the process to proceed to step SP306 andends sub-routine SRT3 of the tag generation process.

2-6. Information Introduction Processing Sequence

Next, an information introduction processing sequence performed by theplurality of information display terminals 11 and 12 and the informationsharing apparatus 14 will be described with reference FIGS. 46 and 47.The reference numerals are given to the constituent elementscorresponding to the elements in FIG. 40.

At this time, the control unit 20 of the plurality of informationdisplay terminals 11 and 12 starts a data supply processing sequence RT2shown in FIG. 46 in cooperation with each circuit unit, for example,when the user gives a request for displaying ht electronic book andgives a request for transmitting the book association data wheneverselecting the desired part.

At this time, when the control unit 20 of the plurality of informationdisplay terminals 11 and 12 starts the data supply processing sequenceRT3, the control unit 20 performs the processes of step SP1 and step SP2and waits until the desired part is instructed in the text of theelectronic book image being displayed.

When the desired part in the text of the electronic book image beingdisplayed is instructed, the control unit 20 sequentially performs stepSP3 to step SP9. Then, the process proceeds to step SP21.

Then, in step SP21, the control unit 20 allows the retrieval unit 66 toretrieve the book association data regarding the selected desired part.In addition, the control unit 20 transmits both the retrieved bookassociation data and the user registration information from thetransmission unit 23 to the information sharing apparatus 14 via thenetwork 13. Then, the process proceeds to step SP2.

For example, the control unit 20 transmits the book association dataregarding the desired part to the information sharing apparatus 14, forexample, whenever the desired part is instructed in the text of theelectronic book image being displayed.

For example, when a request for ending the display of the electronicbook ends, the process proceeds to step SP22 and the control unit 20ends the data supply processing sequence RT2.

On the other hand, the control unit 110 of the information sharingapparatus 14 starts a user introduction processing sequence RT3 shown inFIGS. 46 and 47. When the control unit 110 of the information sharingapparatus 14 starts the user introduction processing sequence RT3, thecontrol unit 110 receives determines whether the book association dataare transmitted from the information display terminals 11 and 12 and arereceived in step SP31.

As a consequence, when the book association data are not transmittedfrom the information display terminals 11 and 12 and thus the controlunit 110 of the information sharing apparatus 14 obtains a negativeresult in step SP31, the process proceeds to step SP32.

In step SP32, the control unit 110 of the information sharing apparatus14 determines whether the introduction request data are transmitted fromthe information display terminals 11 and 12 and are received. As aconsequence, when the introduction request data are not transmitted fromthe information display terminals 11 and 12 and thus the control unit110 of the information sharing apparatus 14 obtains a negative result instep SP32, the process proceeds to step SP33.

In step SP33, the control unit 110 of the information sharing apparatus14 determines whether the other user notification data are transmittedfrom the information display terminals 11 and 12 and are received. As aconsequence, when the other user notification data are not transmittedfrom the information display terminals 11 and 12 and thus the controlunit 110 of the information sharing apparatus 14 obtains a negativeresult in step SP32, the process returns to step SP31.

Thereafter, the control unit 110 of the information sharing apparatus 14repeatedly performs the processes from step SP31 to step SP33, until thecontrol unit 110 receives the book association data, the introductionrequest data, or the other user notification data.

Thus, the control unit 110 of the information sharing apparatus 14 waitsto receive the book association data, the introduction request data, andthe other user notification data transmitted from the informationdisplay terminals 11 and 12.

When the control unit 110 of the information sharing apparatus 14 allowsthe reception unit 112 to receive the book association data and the userregistration information transmitted from the information displayterminals 11 and 12 and thus obtains a positive result in step SP31, theprocess proceeds to step SP34.

In step SP34, the control unit 110 of the information sharing apparatus14 stores the received book association data and the received userregistration information in association with the book association dataand the user registration information in the storage unit 111, and thenthe process proceeds to step SP32.

Thus, when the book association data and the user registrationinformation are transmitted from the information display terminals 11and 12, the control unit 110 of the information sharing apparatus 14receives and stores the book association data and the user registrationinformation in the storage unit 111 to accumulate the book associationdata for each user in a manageable manner.

Here, when the control unit 20 of the information display terminals 11and 12 receives a request for introducing other users with a preferencesimilar to that of the own user from the user, the control unit 20starts an information sharing processing sequence RT4 shown in FIGS. 46and 47.

When the control unit 20 of the information display terminals 11 and 12starts the information sharing processing sequence RT4, the control unit20 generates the introduction request data and transmits theintroduction request data from the transmission unit 23 to theinformation sharing apparatus 14 via the network 13 in step SP41.

At this time, the control unit 110 of the information sharing apparatus14 waits to receive the introduction request data. Therefore, when thecontrol unit 110 receives the introduction request data and thus obtainsa positive result in step SP32, the process proceeds to step SP35.

In step SP35, the filtering processing unit 114 of the informationsharing apparatus 14 performs the emphasis filtering process using thebook association data between the introduction request user and theother users. Then, the process proceeds to step SP36.

In step SP36, the filtering processing unit 114 of the informationsharing apparatus 14 generates the user introduction data indicating theother users introduced to the introduction request user based on theresult of the emphasis filtering process. Then, the filtering processingunit 114 of the information sharing apparatus 14 transmits the userintroduction data from the transmission unit 113 to the informationdisplay terminals 11 and 12 via the network 13.

At this time, in step SP42, the reception unit 24 of the informationdisplay terminals 11 and 12 receives the user introduction datatransmitted from the information sharing apparatus 14 and transmits theuser introduction data to the control unit 20.

Accordingly, in step SP43, the control unit 20 of the informationdisplay terminals 11 and 12 allows the display control unit 26 todisplay the user introduction list image on the display unit 21 based onthe user introduction data. Then, the process proceeds to step SP44.

in step SP44, the control unit 20 of the information display terminals11 and 12 determines whether the introduction request user selects oneof the users from the user introduction list image. As a consequence,when the introduction request user selects one of the users from theuser introduction list image and thus the control unit 20 of theinformation display terminals 11 and 12 obtains a positive result instep SP44, the process proceeds to step SP45.

In step SP45, the control unit 20 of the information display terminals11 and 12 transmits the other user notification data indicating theother user selected by the introduction request user from thetransmission unit 23 to the information sharing apparatus 14 via thenetwork 13.

At this time, when the control unit 110 of the information sharingapparatus 14 receives the other user notification data transmitted fromthe information display terminals 11 and 12 and thus obtains a positiveresult in step SP33, the control unit 110 allows the process to proceedto step SP37.

In step SP37, the filtering processing unit 114 of the informationsharing apparatus 14 generates the book introduction data used tointroduce single or a plurality of electronic books among the electronicbooks acquired by the other users with the preference similar to that ofthe introduction request user based on the other user notification data.

Then, the filtering processing unit 114 of the information sharingapparatus 14 transmits the book introduction data from the transmissionunit 113 to the information display terminals 11 and 12 via the network13, and then the process proceeds to step SP31.

At this time, in step SP46, the control unit 20 of the informationdisplay terminals 11 and 12 allows the reception unit 24 to receive thebook introduction data transmitted from the information sharingapparatus 14. Then, the process proceeds to step SP47.

In step SP47, the control unit 20 of the information display terminals11 and 12 allows the display control unit 26 to display the bookintroduction image on the display unit 21 based on the book introductiondata. Then, the process proceeds to step SP48. Thus, in Step SP48, thecontrol unit 20 of the information display terminals 11 and 12 ends theintroduction sharing processing sequence RT4.

When the control unit 110 of the information sharing apparatus 14receives the introduction request data transmitted from the informationdisplay terminals 11 and 12 while accumulating the book association datatransmitted from the information display terminals 11 and 12, thecontrol unit 110 introduces the other users with the similar preferenceto the introduction request user.

When the control unit 110 of the information sharing apparatus 14receives the book introduction data transmitted from the informationdisplay terminals 11 and 12 at the time of the introduction of the otherusers, the control unit 110 can introduce the electronic book suggestedby the other users with the preference similar to that of theintroduction request data.

2-7. Information Sharing Processing Sequence

Next, information sharing processing sequences RT5 and RT6 of mutuallyreflecting the desired parts selected by the users of the plurality ofinformation display terminals 11 and 12 will be described with referenceto FIG. 48. The reference numerals are given to the constituent elementscorresponding to the elements in FIG. 40.

Hereinafter, a case will be described in which the information displayterminals 11 and 12 share information by executing direct communicationone another without using the information sharing apparatus 14.

When the user gives a request for displaying the electronic book and arequest for sharing information between the other information displayterminals 11 and 12, the control unit 20 of one of the informationdisplay terminals 11 and 12 starts the information sharing processingsequence RT5 shown in FIG. 48.

When the information sharing processing sequence RT5 starts, the controlunit 20 of one of the information display terminals 11 and 12 determineswhether the desired part is instructed in the text of the electronicbook image being displayed in step SP1.

When a negative result is obtained in step SP1, for example, thenegative result indicates that the user is reading the text of theelectronic book image. When the control unit 20 of one of theinformation display terminals 11 and 12 obtains the negative result instep SP1, the process proceeds to step SP51.

In step SP51, the control unit 20 of one of the information displayterminals 11 and 12 determines whether the book association datatransmitted in response to the selection of the desired part of the sameelectronic book is received from the other of the information displayterminals 11 and 12.

When a negative result is obtained in step SP51, for example, thenegative result indicates that the user of the other of the informationdisplay terminals 11 and 12 is reading the text of the electronic bookimage being displayed. When the control unit 20 of the one of theinformation display terminals 11 and 12 obtains the negative result instep SP51, the process proceeds to step SP2.

Then, in step SP2, the control unit 20 of the one of the informationdisplay terminals 11 and 12 determines whether the display of theelectronic book ends. When the control unit 20 obtains a negative resultin step SP2, for example, the negative result indicates that the user isreading the text of the electronic book image being displayed.Accordingly, when the control unit 20 of the one of the informationdisplay terminals 11 and 12 obtains the negative result in step SP2, theprocess returns to step SP1.

Thereafter, the control unit 20 of the one of the information displayterminals 11 and 12 circularly and repeatedly performs the processes ofstep SP1, step SP51, and step SP2, until the control unit 20 obtains apositive result in step SP1, step SP51, and step SP2.

Thus, the control unit 20 of the one of the information displayterminals 11 and 12 receives the desired part in the text of theelectronic book image, receives the book association data transmittedfrom the other of the information display terminals 11 and 12, and waitsuntil the control unit 20 receives a request for ending the display ofthe electronic book.

When the control unit 20 of the one of the information display terminals11 and 12 obtains the positive result due to the fact that the desiredpart is instructed in the text of the electronic book image beingdisplayed in step SP1, the control unit 20 sequentially performs theprocesses of step SP3 to step SP9. Then, the process proceeds to stepSP52.

In step SP52, the control unit 20 of the one of the information displayterminals 11 and 12 allows the retrieval unit 66 to retrieve the bookassociation data regarding the selected desired part. Then, the controlunit 20 of the one of the information display terminals 11 and 12transmits the book association data from the transmission unit 23 to theother of the information display terminals 11 and 12. Then, the processproceeds to step SP51.

At this time, the control unit 20 of the other of the informationdisplay terminals 11 and 12 also starts an information sharingprocessing sequence RT6 shown in FIG. 48 in response to the user requestfor displaying the electronic book and the user request of sharing theinformation between the other information display terminals 11 and 12.

When the control unit 20 of the other of the information displayterminals 11 and 12 starts the information sharing processing sequenceRT6, the control unit 20 also determines whether the desired part isinstructed in the text of the electronic book image being displayed instep SP1.

When a negative result is obtained in step SP1, for example, thenegative result indicates that the user is reading the text of theelectronic book image. When the control unit 20 of the other of theinformation display terminals 11 and 12 obtains the negative result instep SP1, the process proceeds to step SP61.

In step SP61, the control unit 20 of the other of the informationdisplay terminals 11 and 12 determines whether the book association datatransmitted in response to the selection of the desired part of the sameelectronic book is received from the one of the information displayterminals 11 and 12.

When a negative result is obtained in step SP61, for example, thenegative result indicates that the user of the one of the informationdisplay terminals 11 and 12 is reading the text of the electronic bookimage being displayed. When the control unit 20 of the other of theinformation display terminals 11 and 12 obtains the negative result instep SP61, the process proceeds to step SP2.

In step SP2, the control unit 20 of the other of the information displayterminals 11 and 12 determines whether the display of the electronicbook ends. When a negative result is obtained in step SP2, for example,the negative result also indicates that the user is reading the text ofthe electronic book image being displayed. Accordingly, when the controlunit 20 of the other of the information display terminals 11 and 12obtains the negative result in step SP2, the process returns to stepSP1.

Thereafter, the control unit 20 of the other of the information displayterminals 11 and 12 circularly and repeatedly performs the processes ofstep SP1, step SP61, and step SP2, until the control unit 20 obtains apositive result in SP1, step SP61, and step SP2.

Thus, the control unit 20 of the other of the information displayterminals 11 and 12 receives the desired part in the text of theelectronic book image, receives the book association data transmittedfrom the other of the information display terminals 11 and 12, and waitsuntil the control unit 20 receives a request for ending the display ofthe electronic book.

When the control unit 20 of the other of the information displayterminals 11 and 12 obtains the positive result due to the fact that thereception unit 24 receives the book association data transmitted fromthe one of the information display terminals 11 and 12 in step SP61, theprocess proceeds to step SP63.

In step SP63, the control unit 20 of the other of the informationdisplay terminals 11 and 12 stores the book association data in thestorage unit 25. Then, the process proceeds to step SP64.

In step SP64, the control unit 20 of the other of the informationdisplay terminals 11 and 12 determines whether the desired part selectedin the one of the information display terminals 11 and 12 is displayedin the emphasis manner.

When a positive result is obtained in step SP64, the positive resultindicates that the same page of the same electronic book is currentlybeing displayed in both of the information display terminals 11 and 12.

When the control unit 20 of the other of the information displayterminals 11 and 12 obtains the positive result in step SP64, theprocess proceeds to step SP65.

In step SP65, based on the acquired book association data, the controlunit 20 of the other of the information display terminals 11 and 12displays the desired part selected by the one of the information displayterminals 11 and 12 in the emphasis manner in the text of the electronicbook image being displayed. Then, the process proceeds to step SP2.

On the other hand, when a negative result is obtained in step SP64, thenegative result indicates that different pages of the same electronicbook are currently being displayed in both of the information displayterminals 11 and 12.

When the control unit 20 of the other of the information displayterminals 11 and 12 obtains the negative result in step SP64, theprocess proceeds to step SP2.

When the control unit 20 of the other of the information displayterminals 11 and 12 obtains the negative result again in step SP2, theprocess returns to step SP1.

Then, when the control unit 20 of the other of the information displayterminals 11 and 12 obtains the positive result in step SP1 due to thefact that the desired part is instructed in the text of the electronicbook image being displayed, the control unit 20 sequentially performsthe process from step SP3 to step SP9. Then, the process proceeds tostep SP62.

In step SP62, the control unit 20 of the other of the informationdisplay terminals 11 and 12 allows the retrieval unit 66 to retrieve thebook association data regarding the selected desired part. Then, thecontrol unit 20 of the other of the information display terminals 11 and12 transmits the book association data from the transmission unit 23 tothe one of the information display terminals 11 and 12. Then, theprocess proceeds to step SP61.

When the control unit 20 of the one of the information display terminals11 and 12 obtains the positive result due to the fact that the receptionunit 24 receives the book association data transmitted from the other ofthe information display terminals 11 and 12 in step SP51, the processproceeds to step SP53.

In step SP53, the control unit 20 of the one of the information displayterminals 11 and 12 stores the book association data in the storage unit25. Then, the process proceeds to step SP54.

In step SP54, the control unit 20 of the one of the information displayterminals 11 and 12 determines whether the desired part selected in theother of the information display terminals 11 and 12 is displayed in theemphasis manner.

When a positive result is obtained in step SP54, the positive resultindicates that the same page of the same electronic book is currentlybeing displayed in both of the information display terminals 11 and 12.

When the control unit 20 of the one of the information display terminals11 and 12 obtains the positive result in step SP54, the process proceedsto step SP55.

In step SP55, based on the acquired book association data, the controlunit 20 of the one of the information display terminals 11 and 12displays the desired part selected by the other of the informationdisplay terminals 11 and 12 in the emphasis manner in the text of theelectronic book image being displayed. Then, the process proceeds tostep SP2.

On the other hand, when a negative result is obtained in step SP54, thenegative result indicates that different pages of the same electronicbook are currently being displayed in both of the information displayterminals 11 and 12.

When the control unit 20 of the one of the information display terminals11 and 12 obtains the negative result in step SP54, the process proceedsto step SP2.

When the control unit 20 of the one of the information display terminals11 and 12 obtains the negative result again in step SP2, the processreturns to step SP1.

Thus, the control units 20 of both one and the other of the informationdisplay terminals 11 and 12 repeatedly perform the process from step SP1to SP9, the process from step SP51 to step SP55, the process from stepSP1 to SP9, and the processes from step SP61 to SP65.

The control units 20 of both one and the other of the informationdisplay terminals 11 and 12 can transmit and share the book associationdata regarding the selected desired part in the state where theelectronic book image of the same electronic book is displayed, wheneverthe desired part is mutually selected.

When a positive result is obtained in step SP2, the positive resultindicates that the user gives a request of ending the display of theelectronic book. When the control unit 20 of the one of the informationdisplay terminals 11 and 12 obtains the positive result in step SP2, theprocess proceeds to step SP56 to end the information sharing processingsequence RT5.

When the control unit 20 of the other of the information displayterminals 11 and 12 also obtains the positive result in step SP2, theprocess proceeds to step SP66 to end the information sharing processingsequence RT6.

2-8. Operations and Advantages of First Embodiment.

When the electronic book image of the electronic book is displayed onthe display unit 21 and the desired part is instructed in the text ofthe electronic book image, the information display terminal 11 and 12with the above-described configuration selects the instruction estimatedpart in the text based on the instruction position.

The information display terminal 11 and 12 specify the desired part inthe instruction estimated part based on the processing result (that is,the analysis result) obtained by performing the natural languageprocessing on the instruction estimated part. The information displayterminal 11 and 12 detects the keyword from the desired part based onthe processing result of the natural language processing.

The information display terminal 11 and 12 automatically generate thetag as a word expressing the meaning of the superordinate concept of thekeyword and associate the generated tag with the desired part.

Accordingly, the information display terminal 11 and 12 can easilyidentify which part the desired part is using the tag by associating thetag with the desired part.

According to the above-described configuration, when the desired part isinstructed in the text of the electronic book, the information displayterminals 11 and 12 select the instruction estimated part based on theinstruction position, perform the natural language processing, specifythe desired part in the instruction estimated part based on theprocessing result, detects the keyword from the desired part, generatethe tag corresponding to the detected keyword, and associate the tagwith the desired part. Thus, the information display terminal 11 and 12can easily identify which part of the desired part is using the tag byassociating the tag with the desired part. Accordingly, the informationdisplay terminals 11 and 12 can considerably improve usability.

The information display terminal 11 and 12 are configured to classifythe desired parts in accordance with the meaning of the superordinateconcept of the keywords detected from the desired parts. Accordingly,the information display terminal 11 and 12 can classify the desiredparts selected by the user into the items which the users are interestin.

That is, the information display terminal 11 and 12 can again recognizethe items which the users themselves are interest in based on theclassification result of the desired parts selected by the users.

Moreover, the information display terminal 11 and 12 perform the naturallanguage processing on the association comments, detect the keyword fromthe association comments based on the processing result, and alsoclassify the association comments in accordance with the meaning of thesuperordinate concept of the keywords.

Accordingly, based on the classification result, the information displayterminal 11 and 12 can easily retrieve not only the desired parts whichthe users are interest in but also the association comments which theusers are interested in.

The information display terminal 11 and 12 detect the keywords from thewhole book text, in which the desired part is not selected, and alsoclassify the detected keywords in accordance with the meaning of thesuperordinate concept.

Accordingly, based on the classification result, the information displayterminal 11 and 12 can easily retrieve phrases, clauses, or the like,which indicate the items which the users are interest in for the text ofthe electronic book in which the desired part is not selected.

3. Second Embodiment 3-1. Configuration of Information Display System

In FIG. 49, Reference Numeral 200 denotes an information display systemaccording to a second embodiment. In the information display system 200,a plurality of information display terminals 201 with a communicationterminal configuration, which is a specific example of theabove-described information processing apparatus 1, are configured tocommunicate with an information sharing apparatus 203 with a serverconfiguration via a network 202 such as the Internet or a LAN (LocalArea. Network).

3-2. Hardware Configuration of Hardware Circuit Block of InformationDisplay Terminal

Next, the hardware circuit configuration of a hardware circuit block ofthe information display terminal 201 will be described with reference toFIG. 50.

In the information display terminal 201, when a user operates anoperation input unit 210 including various kinds of operation keysinstalled a casing surface of the information display terminal 201 or aremote controller, the operation input unit 210 recognizes the operationand an operation input signal is transmitted to an input processing unit211 in response to the operation.

The input processing unit 211 converts the operation input signal intoan operation command by performing a predetermined process on thesupplied operation input signal and transmits the operation command to acentral processing unit (CPU) 213 via a bus 212.

The information display terminal 201 includes a touch panel 215 which isinstalled on the display surface of a display 214. When a touchoperation (that is, a tap operation, a flick operation, and a slideoperation) is executed on the surface of the touch panel 215, the touchpanel 215 detects the touch position of the touch operation in responseto the touch operation and notifies the central processing unit 213 viathe bus 212.

The central processing unit 213 reads various kinds of programs such asbasic programs or application programs stored in advance in a ROM (readOnly Memory) 216 or a hard disk drive 217 to a RAM (Random AccessMemory) 218 via the bus 212.

The central processing unit 213 controls all of the various kinds ofprograms developed on the RAM 218 and performs various kinds ofprocesses in response to predetermined arithmetic processing, anoperation command transmitted from the input processing unit 211, andthe touch position of the surface of the touch panel 215.

The central processing unit 213 accesses the network 202 sequentiallythrough a communication processing unit 219 and a network interface 220and is connected to the network 202 and accesses the information sharingapparatus 203, an electronic book supply apparatus, or the like on thenetwork 202.

When the user gives a request for acquiring the electronic book data ofan electronic book via the operation input unit 210 or the touch panel215, the central processing unit 213 accesses the information sharingapparatus 203, the electronic book supply apparatus, or the like inresponse to the request for acquiring the electronic book of theelectronic book to give a request of the electronic book data.

As a consequence, when the electronic book data is transmitted from theinformation sharing apparatus 203, the electronic book supply apparatus,or the like via the network 202, the central processing unit 213 allowsthe network interface 220 and the communication processing unit 219 toreceive and acquire the electronic book data. Then, the centralprocessing unit 213 transmits the electronic book data to the hard diskdrive 217 to store the electronic book data.

When the user gives a request for displaying the electronic book throughthe operation input unit 210 or the touch panel 215, the centralprocessing unit 213 reads the electronic book data from the hard diskdrive 217 in response to the request for displaying the electronic book.Then, the central processing unit 213 displays the electronic book whichis based on the electronic book data on the display 214 by transmittingthe electronic book data to the display processing unit 221.

In the information display terminal 201, as described above, the centralprocessing 213 basically performs various kinds of processes inaccordance with various kinds of programs stored in the ROM 216 or thehard disk drive 217 and controls each hardware unit.

Accordingly, in the information display terminal 201, the various kindsof programs stored in the ROM 216 or the hard disk drive 217 areappropriately selected so as to correspond to the functions of theinformation display terminals 11 and 12 with the hardware configurationof the function circuit block described above with reference to FIGS. 3and 38.

That is, in the information display terminal 201, various kinds ofprograms are appropriately selected as information processing programsconfigured to execute the emphasis display processing sequence RT1, thedata supply processing sequence RT2, the introduction sharing processingsequence RT4, and the information sharing processing sequences RT5 andRT6 described above.

Thus, in the information display terminal 201, the central processingunit 213 can function as the control unit 20, the selection unit 28, theacquisition units 29 and 100, the natural language processing block 30,the specifying unit 33, the registration unit 34, the detection unit 35,and the tag generation unit 36 described above.

In the information display terminal 201, the central processing unit 213also can function as the association unit 60, the retrieval unit 66, theindex generation unit 67, the link generation unit 75, and theclassification unit 77 described above.

In the information display terminal 201, the operation input unit 210,the input processing unit 211, and the touch panel 215 can function asthe operation unit 22 described above. Moreover, the hard disk drive 217can function as the storage unit 25 described above.

In the information display terminal 201, the communication processingunit 219 and the network interface 220 can function as the transmissionunit 23 and the reception unit 24 described above.

In the information display terminal 201, the display processing unit 221can function as the display control unit 26 described above. Moreover,the display 214 can function as the display unit 21 described above.

Thus, as in the information display terminals 11 and 12, the informationdisplay terminal 201 can perform the emphasis display processingsequence RT1, the data supply processing sequence RT2, the introductionsharing processing sequence RT4, and the information sharing processingsequences RT5 and RT6 described above by appropriately selecting thevarious kinds of programs stored in the ROM 216 or the hard disk drive217 so as to correspond to the functions of the information displayterminals 11 and 12. Accordingly, the information display terminal 201can obtain the same advantages as those of the information displayterminals 11 and 12 of the first embodiment described above.

In the information display terminal 201, an information processingprogram may be stored in advance in the ROM 216 or the hard disk drive217. Moreover, in the information display terminal 201, the informationprocessing program may be installed using a program storage medium whichstores the information processing program.

In the information display terminal 201, the information processingprogram may be installed using a wired or wireless communication mediumsuch as a local area network, the Internet, or digital satellitebroadcasting.

A computer readable storage medium which stores the informationprocessing program installed and executed in the information displayterminal 201 may be realized by a package medium such as a flexibledisk.

Moreover, the computer readable storage medium which stores theinformation processing program installed and executed in the informationdisplay terminal 201 may be realized by a package medium such as aCD-ROM (Compact Disc-Read Only Memory).

Furthermore, the computer readable storage medium which stores theinformation processing program installed and executed in the informationdisplay terminal 201 may be realized by a package medium such as a DVD(Digital Versatile Disc).

The computer readable storage medium may be realized not only by thepackage medium but also a semiconductor memory, a magnetic disk, or thelike which temporarily or permanently various kinds of programs.

As a mechanism for storing the information processing program in thecomputer readable storage medium, a wired or wireless communicationmedium such as a local area network, the Internet, or digital satellitebroadcasting may be used.

The information processing program may also be stored in the computerreadable storage medium via various kinds of communication interfacessuch as routers or modems.

3-3. Hardware Configuration of Hardware Circuit Block of InformationSharing Apparatus

Next, the hardware circuit configuration of the hardware circuit blockof the information sharing apparatus 203 will be described withreference to FIG. 51.

A central processing unit 230 of the information sharing apparatus 203reads various kinds of programs such as basic programs or applicationprograms stored in advance in a ROM 231 or a hard disk drive 232 to aRAM 234 via a bus 233. Moreover, the central processing unit 230controls all of the various kinds of programs developed on the RAM 234and performs various kinds of processes.

The central processing unit 230 stores the electronic book data in thehard disk drive 232. When a request for the electronic book data isgiven from the information display terminal 201, the central processingunit 230 reads the electronic book data from the hard disk drive 232 inresponse to the request for the electronic book data.

Thus, the central processing unit 230 transmits the read electronic bookdata to the information display terminal 201 sequentially through acommunication processing unit 235 and a network interface 236 via thenetwork 202.

In the information sharing apparatus 203, as described above, thecentral processing unit 230 basically executes various kinds ofprocesses in accordance with the various kinds of programs stored in theROM 231 or the hard disk drive 232 and controls each hardware unit.

Accordingly, in the information sharing apparatus 203, the various kindsof programs stored in the ROM 231 or the hard disk drive 232 areappropriately selected so as to correspond to the functions of theinformation sharing apparatus 14 with the hardware configuration of thefunction circuit block described above with reference to FIG. 39.

That is, in the information sharing apparatus 203, various kinds ofprograms stored in the ROM 231 or the hard disk drive 232 areappropriately selected as information processing programs configured toexecute the user introduction processing sequence RT3 described above.

Thus, in the information sharing apparatus 203, the central processingunit 230 can function as the control unit 110 and the filteringprocessing unit 114 described above. In the information sharingapparatus 203, the hard disk drive 232 can function as the storage unit111 described above.

In the information sharing apparatus 203, the communication processingunit 235 and the network interface 236 can function as the transmissionunit 113 and the reception unit 112 described above.

Thus, as in the information sharing apparatus 14, the informationsharing apparatus 203 can perform the user introduction processingsequence RT3 described above by appropriately selecting the variouskinds of programs stored in the ROM 231 or the hard disk drive 232 so asto correspond to the functions of the information sharing apparatus 14.Accordingly, the information sharing apparatus 203 can obtain the sameadvantages as those of the information sharing apparatus 14 of the firstembodiment described above.

In the information sharing apparatus 203, an information processingprogram may be stored in advance in the ROM 231 or the hard disk drive232. Moreover, in the information sharing apparatus 203, the informationprocessing program may be installed using a program storage medium whichstores the information processing program.

In the information sharing apparatus 203, the information processingprogram may be installed using a wired or wireless communication mediumsuch as a local area network, the Internet, or digital satellitebroadcasting.

A computer readable storage medium which stores the informationprocessing program installed and executed in the information sharingapparatus 203 may be realized by a package medium such as a flexibledisk, a CD-ROM, a DVD.

The computer readable storage medium may be realized not only by thepackage medium but also a semiconductor memory, a magnetic disk, or thelike which temporarily or permanently various kinds of programs.

As a mechanism for storing the information processing program in thecomputer readable storage medium, a wired or wireless communicationmedium such as a local area network, the Internet, or digital satellitebroadcasting may be used.

The information processing program may also be stored in the computerreadable storage medium via various kinds of communication interfacessuch as routers or modems.

4. Modification Examples 4-1. Modification Example 1

In the above-described first and second embodiments, the case hashitherto been described in which the desired part is selected from thebody text (text) of an electronic book and the identical structure word,the identical meaning word, or the like is retrieved.

Embodiments of the disclosure are not limited thereto. Instead, thecharacters included in a photo image, or an illustration image, or thelike as well as the body text may be extracted, the desired part may beselected from the extracted characters, and the identical structureword, the identical meaning word, or the like may be retrieved.

4-2. Modification Example 2

In the above-described first and second embodiments, the case hashitherto been described in which the instruction estimated part isselected from the text using the separation character when the desiredpart is instructed.

Embodiments of the disclosure are not limited thereto. Instead, when thedesired part is instructed, the search range may be subjected to naturallanguage processing and the instruction estimated part may be selectedbased on the processing result. Even in this configuration, it ispossible to accurately select the instruction estimated part, as in theabove-described case.

4-3. Modification Example 3

In the above-described first and second embodiments, the case hashitherto been described in which the desired part is instructed in thetext through the touch panel.

Embodiments of the disclosure are not limited thereto. Instead, thedesired part may be instructed by moving a cursor on the text through apointing device such as a joystick or a mouse or a keyboard.

4-4. Modification Example 4

In the above-described first and second embodiments, the case hashitherto been described in which the display state of the emphasisdisplay of the desired part is changed by the importance degree of thedesired part, the person instructing the desired part, or the like.

Embodiments of the disclosure are not limited thereto. Instead, a timeat which the desired part is instructed may be stored as an instructionhistory and the display state of the emphasis display of the desiredpart may be changed in accordance with the instruction time based on theinstruction history.

4-5. Modification Example 5

In the above-described first and second embodiments, the case hashitherto been described in which when the desired part instructed in thetext is specified, the association information such as a home page isretrieved using the retrieval apparatus based on the keywords detectedfrom the specified desired part.

Embodiments of the disclosure are not limited thereto. Instead, when thedesired part instructed in the text is specified, the associatedelectronic book may be retrieved based on the keywords detected from thespecified desired part using the retrieval apparatus from the electronicbooks which the user has not yet acquired.

In the modified example of the disclosure, at this time, not only theelectronic book may be just retrieved, but also a part associated withthe desired part in the whole book text of the retrieved electronic bookmay also be retrieved and introduced.

4-6. Modification Example 6

In the above-described first and second embodiments, the case hashitherto been described in which the association comment input by theuser is associated, as the association information of the desired part,with the tag of the desired part.

Embodiments of the disclosure are not limited thereto. Instead, a videomay be associated, as the association information of the desired part,with the tag of the desired part and the video may be reproduced whenthe tag is instructed.

The video associated with the tag may be stored in the storage unit 25of the information display terminals 11 and 12 or may be reproduced in astreaming manner via the network 13.

4-7. Modification Example 7

In the above-described first and second embodiments, the case hashitherto been described in which the identical structure word and theidentical meaning word are retrieved from the whole book text based onthe keywords included in the desired part and the index or the link listis generated.

Embodiments of the disclosure are not limited thereto. Instead, an indexor a link list of a phrase, a clause, or the like including theidentical structure word or the identical meaning word may be generated.

According to the modified example of the disclosure, when the identicalstructure word is retrieved from the whole book text based on thekeywords included in the desired part, a phrase, a clause, or the likeincluding the retrieved identical structure word is specified in thewhole book text based on the processing result of the natural languageprocessing on the whole book text, the separation character, or thelike.

According to the modified example of the disclosure, when the identicalmeaning word is retrieved from the whole book text based on the keywordsincluded in the desired part, a phrase, a clause, or the like includingthe retrieved identical meaning word is specified in the whole book textbased on the processing result of the natural language processing on thewhole book text, the separation character, or the like.

According to the modified example of the disclosure, the indexgeneration unit 67 generates an index of association portions specifiedand including the identical structure word and an index of associationportions including the identical meaning word.

According to the modified example of the disclosure, the link generationunit 75 generates a link list of association portions specified andincluding the identical structure word and a link list of associationportions including the identical meaning word.

According to the modified example of the disclosure, when the identicalstructure word, the identical meaning word, or the association portionitself is instructed using the index, the text including the associationportion is displayed and the association portion is displayed in theemphasis manner.

According to the modified example of the disclosure, when the identicalstructure word, the identical meaning word, or the association portionitself is instructed using the link list, the text including theassociation portion is displayed and the association portion isdisplayed in the emphasis manner.

With such a configuration, according to the modified example of thedisclosure, the association portion associated with the desired part inthe whole book text can be introduced not as the word but as a phrase, aclause, or the like, when the index or the link list is used.

According to the modified example of the disclosure, the associationportion associated with the desired part can easily be recognized in thewhole book text even when some range including the identical structureword or the identical meaning word on purpose is read.

In the above-described first and second embodiments, the identicalstructure word and the identical meaning word have been displayed in theemphasis manner in different display state in accordance with theattribute in which the identical structure word or the identical meaningword is identical to the keyword in the structure or meaning.

According to the modified example of the disclosure, the associationportion can be displayed in the emphasis manner in different displaystate in accordance with the attribute (that is, which word is includedbetween the identical structure word or the identical meaning word).Accordingly, According to the modified example of the disclosure, it ispossible to easily determine the degree that the association portion isassociated with the desired part.

According to the modified example of the disclosure, when the textincluding the association portion is displayed based on the index or thelink list, the association portion is displayed in the emphasis manner.In addition, when the electronic book image to be displayed is newlyswitched by the user operation, it is automatically determined whetherthe association portion is included in the text of the electronic bookimage after the display switch based on the index or the link list.

According to the modified example of the disclosure, when theassociation portion is included in the text of the electronic book imageafter the display switch, the association portion may be displayed inthe emphasis manner.

4-8. Modification Example 8

In the above-described first and second embodiments, the case hashitherto been described in which the desired parts and the associationcomments are classified in accordance with the meaning of thecorresponding keywords and the folder name.

Embodiments of the disclosure are not limited thereto. Instead, thedesired parts and the association comments may be classified inaccordance with the corresponding tags (that is, the meanings expressingthe tags) or the tag expressing the meaning identical or similar to thefolder name.

4-9. Modification Example 9

In the above-described first and second embodiments, the case hashitherto been described in which the keywords are detected from thewhole book text of the electronic book, in which the desired part is notselected, and the keywords are classified based on the folder name andthe meaning of the superordinate concept of the keywords.

Embodiments of the disclosure are not limited thereto. Instead, thekeywords are detected from the whole book text of the electronic book inwhich the desired part is not selected. According to the modifiedexample of the disclosure, among the detected keywords, the keywordshaving the meaning of the superordinate concept identical or similar tothe meaning expressed by the tag may be classified together with thedesired part based on the tag of the desired part.

According to the modified example of the disclosure, the words havingthe meaning of the superordinate concept identical or similar to themeaning expressed by the tag of the desired part already selected fromthe whole text of the electronic book are detected as the keywordsirrespective of whether the desired part is selected. According to themodified example of the disclosure, the detected keywords may beclassified together with the desired part.

4-10. Modification Example 10

In the above-described first and second embodiments, the case hashitherto been described in which when the electronic book imageincluding the desired part is displayed, the keywords detected from thedesired part are transmitted to the advertisement supply apparatus andan advertisement is supplied.

Embodiments of the disclosure are not limited thereto. Instead, when theelectronic book image including the desired part is displayed, the tagcorresponding to the desired part may be transmitted to theadvertisement supply apparatus and an advertisement may be supplied.According to the modified example of the disclosure, with such aconfiguration, an advertisement highly associated with the desired partcan be supplied, even when the desired part includes the plurality ofkeywords.

According to the modified example of the disclosure, when the tags (orkeywords) are transmitted, not only an advertisement may be supplied,but also an association book associated with the desired part or openassociation information or the like associated with the desired part maybe announced or supplied.

4-11. Modification Example 11

In the above-described first and second embodiments, the case hashitherto been described in which the information processing apparatusaccording to the embodiments of the disclosure is applied to theinformation display terminals 11, 12, and 201 shown in FIGS. 1 to 51.

Embodiments of the disclosure are not limited thereto. Instead, theinformation processing apparatus is applicable to an informationprocessing apparatus such as a computer, a portable telephone, a PDA(Personal Digital Assistance), and a portable game console.

4-12. Modification Example 12

In the above-described first and second embodiments, the case hashitherto been described in which the selection units 2 and 28 and thecentral processing unit 213 described with reference to FIGS. 1 to 51are applied as the selection unit that selects at least a part of thetext forming contents.

Embodiments of the disclosure are not limited thereto. Instead,selection units are widely applicable which have various configurationssuch as a selection circuit, a microprocessor, and a DSP (Digital SignalProcessor) with a hardware circuit configuration that selects at least apart of the text forming contents.

4-13. Modification Example 13

In the above-described first and second embodiments, the case hashitherto been described in which the acquisition units 3, 29, and 100and the central processing unit 213 described with reference to FIGS. 1to 51 are applied as an acquisition unit that acquires the processingresult of the natural language processing on a part of the text selectedby the selection unit.

Embodiments of the disclosure are not limited thereto. Instead,acquisition units are widely applicable which have variousconfigurations such as an acquisition circuit with a hardware circuitconfiguration, a microprocessor, and a DSP (Digital Signal Processor)that, acquires the processing result of the natural language processingon a part of the text selected by the selection unit.

4-14. Modification Example 14

In the above-described first and second embodiments, the case hashitherto been described in which the specifying units 4 and 33 and thecentral processing unit 213 described with reference to FIGS. 1 to 51are applied as a specifying unit that specifies a predetermined part ofthe text based on the processing result acquired by the acquisitionunit.

Embodiments of the disclosure are not limited thereto. Instead,specifying units are widely applicable which have various configurationssuch as a specifying circuit with a hardware circuit configuration, amicroprocessor, and a DSP that specifies a predetermined part of thetext based on the processing result acquired by the acquisition unit.

4-15. Modification Example 15

In the above-described first and second embodiments, the case hashitherto been described in which the detection units 5 and 35 and thecentral processing unit 213 described with reference to FIGS. 1 to 51are applied as a detection unit that detects the keywords from apredetermined part of the text based on the processing result acquiredby the acquisition unit.

Embodiments of the disclosure are not limited thereto. Instead,detection units are widely applicable which have various configurationssuch as a detection circuit with a hardware circuit configuration, amicroprocessor, and a DSP that detects a predetermined part of the textbased on the processing result acquired by the detection and acquisitionunits.

4-16. Modification Example 16

In the above-described first and second embodiments, the case hashitherto been described in which the tag generation units 6 and 36 andthe central processing unit 213 described with reference to FIGS. 1 to51 are applied as a tag generation unit that automatically generates thetag corresponding to the keyword detected by the detection unit.

Embodiments of the disclosure are not limited thereto. Instead, taggeneration units are widely applicable which have various configurationssuch as a tag generation circuit with a hardware circuit, amicroprocessor, and a DSP configuration that automatically generates thetag corresponding to the keyword detected by the detection unit.

4-17. Modification Example 17

In the above-described first and second embodiments, the case hashitherto been described in which the association units 7 and 60 and thecentral processing unit 213 described with reference to FIGS. 1 to 51are applied as an association unit that associates the tag generated bythe tag generation unit with a predetermined part of the text.

Embodiments of the disclosure are not limited thereto.

Instead, association units are widely applicable which have variousconfigurations such as an association circuit with a hardware circuitconfiguration, a microprocessor, and a DSP that associates the taggenerated by the tag generation unit with a predetermined part of thetext.

4-18. Modification Example 18

In the above-described first and second embodiments, the case hashitherto been described in which the classification unit 77 and thecentral processing unit 213 described with reference to FIGS. 1 to 51are applied as a classification unit that classifies predetermined partsof the text based on the tags.

Embodiments of the disclosure are not limited thereto. Instead,classification units are widely applicable which have variousconfigurations such as a classification circuit with a hardware circuitconfiguration, a microprocessor, and a DSP that classifies predeterminedparts of the text based on the tags.

4-19. Modification Example 19

In the above-described first and second embodiments, the case hashitherto been described in which the display control unit 26 and thedisplay processing unit 221 described with reference to FIGS. 1 to 51are applied as a display control unit that controls the display of apredetermined part of the text.

Embodiments of the disclosure are not limited thereto. Instead, displaycontrol units with various configurations such as a microprocessor or aDSP performing display based on the tag are widely applicable.

4-20. Modification Example 20

In the above-described first and second embodiments, the case hashitherto been described in which the transmission unit 23, thecommunication processing unit 219, and the network interface 220described with reference to FIGS. 1 to 51 are applied as a transmissionunit that transmits the tag associated with the predetermined part to anexternal apparatus when the predetermined part is displayed.

Embodiments of the disclosure are not limited thereto. Instead,transmission units with various configurations are widely applicable inaccordance with a method of communicating with the external apparatus.

4-21. Modification Example 21

In the above-described first and second embodiments, the case hashitherto been described in which the reception unit 24, thecommunication processing unit 219, and the network interface 220described with reference to FIGS. 1 to 51 are applied as a receptionunit that receives information associated with the tag replied from anexternal apparatus in response to the transmission of the tag from thetransmission unit.

Embodiments of the disclosure are not limited thereto. Instead,reception units with various configurations are widely applicable inaccordance with a method of communicating with the external apparatus.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2010-166327 filed in theJapan Patent Office on Jul. 23, 2010, the entire contents of which arehereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. An information processing apparatus comprising: a selection unit selecting at least a part of a text included in contents; an acquisition unit acquiring a processing result of natural language processing for the part of the text selected by the selection unit; a specifying unit specifying a predetermined part of the text based on the processing result acquired by the acquisition unit; a detection unit detecting a keyword from the predetermined part of the text based on the processing result acquired by the acquisition unit; a tag generation unit automatically generating a tag in accordance with the keyword detected by the detection unit; and an association unit associating the tag generated by the tag generation unit with the predetermined part of the text.
 2. The information processing apparatus according to claim 1, wherein the tag generation unit generates the tag as a word expressing a meaning of a superordinate concept for the keyword.
 3. The information processing apparatus according to claim 2, further comprising: a classification unit classifying the predetermined part of the text based on the tag.
 4. The information processing apparatus according to claim 3, wherein the classification unit classifies the predetermined part of the text based on the tag expressing a meaning which accords with or is similar to the meaning of the superordinate concept in accordance with the meaning of the superordinate concept arbitrarily selected.
 5. The information processing apparatus according to claim 4, wherein the selection unit selects the entire text, wherein the detection unit detects the keywords from the entire text, and wherein the classification unit classifies the keywords of which the meaning of the superordinate concept accords with or is similar to the meaning expressed by the tag among the keywords detected from the entire text together with the predetermined part of the text.
 6. The information processing apparatus according to claim 4, wherein the selection unit selects the entire text, and wherein the detection unit detects, as keywords, words of which the meaning of the superordinate concept accords with or is similar to the meaning expressed by the tag from the entire text.
 7. The information processing apparatus according to claim 4, further comprising: a display control unit performing control to display the predetermined part of the text; a transmission unit transmitting the tag associated with the predetermined part of the text to an external apparatus, when the predetermined part is displayed; and a reception unit receiving information regarding the tag which is returned from the external apparatus when the transmission unit transmits the tag, wherein the display control unit performs the control to display both the predetermined part of the text and the information received by the reception unit.
 8. An information processing method comprising: selecting at least a part of a text included in contents; acquiring a processing result of natural language processing for the selected part of the text; specifying a predetermined part of the text based on the acquired processing result; detecting a keyword from the predetermined part of the text based on the acquired processing result; automatically generating a tag corresponding to the detected keyword; and associating the tag with the predetermined part of the text.
 9. An information processing program causing a computer to execute: selecting at least a part of a text included in contents; acquiring a processing result of natural language processing for the selected part of the text; specifying a predetermined part of the text based on the acquired processing result; detecting a keyword from the predetermined part of the text based on the acquired processing result; automatically generating a tag corresponding to the detected keyword; and associating the tag with the predetermined part of the text. 